Matt Peters: Today on the podcast, we have Lynda Bell from the National Geodetic Survey. Lynda reached out to us because, I don’t know if any of you remember, Bill Stone, who was our representative, has since retired. Lynda has come up to the big city of Salt Lake and we made some different visits. Also with me today I have Greg Bunce of course, my sidekick in crime.
You know, there were a few reasons why Lynda came up to see us here in Utah. There were a few projects going on, but also to see what we were doing. And for me, being the director of UGRC, I wanted to understand more how we fit into the NGS and how they can help us and how we can help them. What collaborative efforts have we got there? Because recently, as you all know, we’re expecting a new 2022 reference frame as NAD 83 is going away and the vertical reference frame is going away and we’re getting new, more accurate state plane pieces. So we just wanted to have a little chat about that. Greg, do you have anything to add?
Greg Bunce: No, I think that’s great. Maybe Lynda can introduce herself and kind of give us a who she is and what she does.
Lynda Bell: Thanks Matt and thanks Greg. It’s so great to be here with you guys today. I am the NOAA National Geodetic Survey Southwest Regional Geodetic Advisor. I on-boarded in the position a little over a year ago and I support Arizona, New Mexico, and Utah. And like Matt said, I was just up there for a visit getting to meet some of you fine folks at UGRC, worked with the United States Geological Survey and we worked with the Mormon Temple when I was there. So I’m excited to step into the shoes that Bill Stone so effectively set out in this position and continue to serve you guys and serve the region.
Matt Peters: That sounds great. So when people think about NGS, I wonder what they think of? And if you had to describe NGS, say how kind of does it affect our day-to-day lives, what would you say?
Lynda Bell: Well, I’d like to just formally state the mission and then a little bit after that how it affects our everyday lives. The mission of the National Geodetic Survey is to define and maintain and provide access to the National Spatial Reference System, sometimes called the NSRS. This provides a consistent coordinate system that defines latitude, longitude, height, scale, gravity, and orientation through the United States and its territories.
As accuracy and precision of geospatial data increases, it is becoming more and more important to manage our data carefully and to use consistent reference frames. NGS then defines datums to help align data and tools to transform coordinates. This improves all geospatial data in our local areas and on our nation. Geospatial data really is the underpinning of everything from weather imagery to national infrastructure such as roads, bridges, waterways, natural disaster response, communications, climate change research, national and international security and many, many other uses.
We use geospatial data every day on our smartphones, in our cars, on our computers to check everything from the weather, navigate ourselves when driving or communicate with the outside world, and to inform and educate ourselves about the world around us. So understanding these reference frames and accurately defining them is really important to almost, it touches almost everything in our everyday lives.
Matt Peters: Yeah, and I definitely agree with you there, this idea that it touches everything. When I think about land ownership, whether it’s federal or private, or the boundary between federal and private, or describing things crossing public or private land, the National Reference System, it definitely is what ties it together.
Lynda Bell: I think of it as putting a pin on it, Matt. Just pinning all those layers of information together.
Matt Peters: Yeah, yeah. Kind of the framework for all our GIS work.
Lynda Bell: That’s right.
Greg Bunce: And Lynda, when you talk about the spatial frames, those are the datums, right?
Lynda Bell: That’s right.
Greg Bunce: And that’s kind of a thing, maybe we can go in that direction for a second because I think that’s one of the, as geospatial folks, that’s probably the one thing that all of us deal with and work with, but it can be a little bit confusing and mysterious to us. We work with them, we almost like adopt a datum and then it’s just in the background and we do our work, but we address it infrequently unless we have to transform data that we get from someone else. But typically we lock into a projection and we know we have a datum. But so the NGS is really responsible for creating this datum and it sounds like there’s three or so of them currently going, is that right?
Lynda Bell: That’s right. Yeah, and that’s a really great question Greg. And I was just at AGIC down in Prescott with Michael Dennis, who’s our State Plane Coordinate System manager for NGS. And as we sort of spoke and we did a sort of panel presentation, we had people asking specific questions, but really where I got the real questions and what everyone wanted to know is just what you asked: what’s a datum? So when I was standing in the lunch line with my plate in my hand, that’s when people started to come up and they really just wanted to have a conversation about it. So I’m happy to answer that question and I’ll try to use some analogies today to maybe put it in terms that we can all understand.
So first of all, like you said, datums really are the basis for all geodetic survey work. So even though we kind of take them for granted in the background, NGS is actually paying attention and making sure, since they are the underpinning of all these reference frames that we work from, that we understand that we’re defining it properly.
So a general explanation of a geodetic datum is to think of a datum like similar to starting points when you give someone directions. By definition, a geodetic datum is an abstract coordinate system with a reference surface, like sea level, that serves to provide a known location that we use to begin our surveys or create our maps. For instance, when you want to tell someone how to get to your house, you give them a starting point that they know like a crossroads or a building address. And then geodesists and surveyors use datums to create starting or reference points for things like floodplain maps and property boundaries, construction surveys, levee design or other work requiring accurate coordinates that are consistent with one another.
Right now there are two main datums in the US. And we again think of it as our directions. How do we find our directions from some point? So these two main datums are defined as a horizontal datum that measures positions in latitude and longitude on the surface of the earth, and a vertical datum used to measure land elevations and water depths.
Right now NOAA and partners are now working on three major datum updates. Our scientists at NOAA CO-OPS are updating the National Tidal Datum Epoch. This is what we use to measure water levels all along the US coast. That’ll help improve navigation safety, storm surge projection, sea level monitoring, and ecosystem research.
Currently right now, just a couple weeks ago, US and Canadian partners came together with NOAA NGS and they’re undertaking this huge initiative to update the International Great Lakes Datum. And that’s going to deliver more accurate water level measurements through the Great Lakes. So we have big teams of international partners up there right now in the Great Lakes taking measurements all along the Great Lakes coastline.
Scientists at the National Geodetic Survey are working on a long term project to make accurate height measurement better, faster and cheaper. This really is the underpinning of what we call the modernization of the NSRS. And this project is GRAV-D or Gravity for Redefinition of the American Vertical Datum. And it’s just planes flying gravity surveys across the whole country. And we’ve been doing it for a while. And I think this year we’re getting close to finishing all of those up. And that is basically us looking at things from above instead of just depending on what we’ve measured only on the ground. And I’ll talk a little bit more about that in some of our further discussion here today.
But when we complete this GRAV-D survey, our hope is that users will begin to get accurate heights to within about 2 to 3 centimeters, which is pretty amazing. I know some surveys that folks are working on, they may not need more than even a half meter of accuracy, but certainly when we’re doing science, we need to be looking at accuracies of at least 2 to 3 centimeters in the vertical and only 1 to 2 in the horizontal. If we’re looking at small movements on the earth’s crust, that accuracy is very important. And so using these these new vast datasets that we’re creating mixed with historic data that’s been collected across benchmarks across the country is all helping us to better define this geodetic datum. And it’s really again a coordinate system with a reference surface.
Greg Bunce: And I like the way you have an analogy for it. I think that’s the best way that we can wrap our heads around it, the folks who use it less often than you do. Your colleague Brian Shaw from the Rocky Mountain region, he’s got a pretty good analogy as well. And I like your one with directions. I recall him describing it essentially like as your kids are growing up you mark the lines on the wall and you keep marking them as they grow and you get all these lines on the wall for how tall they are. But the datum really is the floor. And if you put carpet in or if you take the carpet out or put hardwood in, now you’ve just changed the reference point and the datum and the measurements and the markings are not consistent anymore.
So the current one is NAD 83, correct? And you folks are working toward replacing NAD 83?
Lynda Bell: Yes, yes we are. And so we’re going to be including, Greg and I talked about this, some specific notes that give more detail where people can really come in and really read more about what we’re doing. And so I’m going to make sure that I don’t speak to too much of that data, but I do want to make sure that you know that it’ll be there for you to read in depth more about this question that Greg just answered.
But in general, what’s going on with the new datum is that we’re replacing the official NAD 83 and NAVD 88 that’s currently the underpinning of the National Spatial Reference System. And although they’re still the official geometric and geopotential datums of the NSRS, they’ve been identified as having shortcomings, sort of like what Greg was just talking about putting the carpet in and removing it. And those shortcomings we feel at NGS are best addressed through defining new horizontal and vertical datums.
So these new definitions are going to address the fact that here’s what those shortcomings are. Right now NAD 83 is non-geocentric by about 2.2 meters and the vertical 88 is both biased and tilted relative to the best global geoid models we have today. So why we have these issues just derives from the fact that both datums were defined initially using terrestrial surveying techniques at passive geodetic marks. Now we have these more modern techniques of observing the earth’s surface from space. That network of historic survey marks just age and deteriorate over time. Both through unchecked physical movement, we could have subsidence, we could have construction that disturbs the movement, we could be in a tectonically active area. Sometimes they’re just simply removed and nobody knows what to do, you know, that they’re supposed to try to resurvey that mark and tie it back into the database. Sometimes they call us at NGS and we help them with that process. Sometimes they just don’t know and they’re just removed. And so if that was the underpinning of the network of understanding those datums and we’re losing those survey marks or they’re deteriorating, then we’ve got the carpet problem again. And something’s moving that we don’t understand in that datum. So updating with all the new space geodetic data that we’ve been collecting over the last 20 years is really what is allowing us to modernize this datum.
So we’re going to replace all three NAD 83 frames and all vertical datums with four new terrestrial reference frames and a geopotential datum. The new reference frames are going to rely primarily on GPS or the Global Navigation Satellite System it’s within. So if you’ve been part of GPS for a while, we started out where all we had was a suite, I think when I first started surveying for NASA, we had 20 maybe satellites I think that we could see. They were just GPS. Now we have GPS satellites from all over the world and that is a larger array called the Global Navigation Satellite System. That just gives us more satellites in the sky, more sky coverage, and a better chance to to capture at our receivers when we’re surveying much more accurate points. So we will be using primarily that data as well as the GRAV-D gravimetric data that I was talking about that’s being flown across the country right now.
These new reference frames will be easier to access and maintain than the current one, which relies on these old physical survey markers that deteriorate over time. So we’re going to call that new reference system the Modernized NSRS. The release of the Modernized NSRS was initially projected to be this year and so it will be named the NSRS 2022 or the SPCS 2022 for State Plane, but the actual projected release date for both is is now looking to be sometime in 2025.
Matt Peters: You know, there was just to take a little side note, can you tell me quick what the GRAV-D survey is?
Lynda Bell: Yes, I know I was throwing a lot of acronyms out quickly. So spelled out that is the Gravity for the Redefinition of the American Vertical Datum Project. GRAV-D. And so we’re flying gravity surveys from airplanes across the country. And we’re ground truthing them too with surveys that are done primarily at airports across the US. So we’ve had several being flown right here in our region of Utah, New Mexico and Arizona just since I’ve been on-boarded. I think there’s been two big airborne GRAV-D surveys flown. So we’re really, that is really what we’re using to redefine the vertical.
Matt Peters: Is it some kind of a LIDAR or what?
Lynda Bell: It’s a gravimeter. Basically, and I think it’s both LIDAR and gravimeter being flown on a plane and measuring as it flies. And then there’s ground-based gravimeters as well. So there’s, I think like I said, most of the ground-based survey points are at airports. And they’re then just ground truthing the flown data. And you know, I’m not sure everything that’s flown from that plane, it could be that we have a combination of data coming in from anything orthometric and all kinds of cool stuff. LIDAR as well.
Matt Peters: So all this, all these things you’re speaking of, what type of educational and experience background did you have?
Lynda Bell: Well, I’ve been at this for a little while and I ended up in geodesy because I started out with a degree in geophysics from Virginia Tech. And the story, can I tell a story, is that okay?
Matt Peters: Sure, sure, sure.
Lynda Bell: Okay. So the very untechnical, unglamorous way that I got my first job, which was at NASA, was I was a sophomore undergraduate in geophysics at Virginia Tech and I had my Virginia Tech sweatshirt on. And I rented a canoe, I was a lifeguard at a campground at a state park in Maryland. And I didn’t know that the person in the family that I was renting a canoe to was a NASA engineer. And he was from UVA and I was, you know, just a young Virginia Tech undergrad. And he teased me about what school I went to because UVA and Tech were rivals and still are. And he said, “What are you studying?” And I told him Geophysics. He said, “That is really interesting. What kind of classes do you take?” I said, “Oh, lots of physics and lots of mathematics and advanced math and I have a minor in geology and a major in geophysics and I’m doing Fourier analysis.” And he said, “All of that as an undergrad?” I said, “Yeah, it’s really hard.” And he said, “You know what, we have an internship program we’re starting up at NASA Goddard for students with backgrounds like yours if you’re interested in it. Here’s my colleague’s name and number.” So I, you know, I just very nervously went home and told my folks about it and they were like, “Oh my gosh, are you kidding? Get in touch with them right away.” So I did and I interviewed and got an internship at NASA Goddard after my sophomore year at undergrad.
And I worked for the Crustal Dynamics Project and the Geodynamics Branch of NASA Goddard. And I worked mostly with radio astronomers who were using VLBI or Very Long Baseline Interferometry, which are those big dishes like you see in the movie Contact with Jodie Foster at the VLBA. And we were just starting to, they had really started to obtain some of the first real measurements of crustal motion when I was an intern. And most of them though were looking at the sky and I and my bosses who were people from like MIT and just these amazing, brilliant, brilliant people said, “We’re going to try to understand what these measurements you’re taking from quasars in deep space are showing us on the earth.” And lo and behold we were seeing as we analyzed the data vectors moving in the directions of plate motion. So I was very, very lucky that just as an intern wide-eyed studying under the masters I got a chance to be part of that early work of geodetic surveying.
And I went out later and started working with GPS and we did footprint networks around the VLBI network. We started working in Alaska studying plate motion there, seismic prediction across the San Andreas Fault in California. So that was really neat to get to be part of that work coming back around later in graduate school, working again supported by NASA but through grants in academia at that time. And so that was my educational path. And then I’ve gotten a chance to work also for the National Park Service when I was in grad school as the Sea Level Specialist improving water level monitoring in US ocean and coastal national parks. I worked a little bit in between all of that grad school and work as an adjunct prof and a curriculum developer for a couple of schools, University of Maryland, a couple of schools back East. And that that gave me some chops on teaching and and how to develop training materials and things, part of which is part of my job now. And now I’m serving as your Southwest Regional Advisor and I’m a full-time civil servant for the US Department of Commerce.
Matt Peters: Wow. You’re making me tired.
Lynda Bell: It was a long path but it was interesting. It really I have to say that the path for me was just driven by curiosity. I was working with brilliant scientists from the very beginning and they taught me to be curious and think outside the box and and always look for the next question to ask. And when I then became a science teacher in college classrooms, that really is what I taught my students, that science really is inquiry. And if we’re doing good science, one question should just answer or lead to another question, not an answer. So I really think I have my early mentors to thank for that that dream. Yeah.
Matt Peters: Yeah. There was one thing I I kind of wondered about with that, you know when when you talked about how you met the gentleman, you know with the canoe. I I can’t tell you how many stories or how often that same kind of thing has played out where you sit down somewhere, have a drink with someone, your paths cross, the future blooms. Yeah, it’s pretty crazy.
Greg Bunce: And I think it’s just staying curious. I think that that’s the key there for me as well. And I and I like to I like that point that you made.
I’m also curious about so you mentioned terrestrial a couple times early on. A lot of the the some of the original datums were all you know based on terrestrial stuff. So I’m thinking of benchmarks and I’m thinking of monuments. And we’ve heard of something called the GPS on Benchmarks and and how some of us get involved in that. Are those referring back to the terrestrial benchmarks and kind of GPSing those? Can you talk a bit about that program?
Lynda Bell: Yeah, most definitely Greg. And that is exactly what it is. By definition, we call it our GPS on Benchmarks or GPS on BM program and it’s just a crowdsourced data collection program that helps your community prepare for the modernization of the NSRS. It’s a little bit like geocaching really for folks that like to go out for fun. A lot of times we have retired surveyors help us, community groups, scout groups will go out, young students who are just training on surveying. It doesn’t you don’t have to be currently employed as a professional to help us with this. But the idea of it is to help us increase our knowledge of geodetic positioning on these these benchmarks in your area.
So for the last 200 years actually, the nation’s foundational mapping infrastructure has relied on hundreds of thousands of survey marks set in the ground across the country. So in 2007 NGS embarked on a decades-long endeavor to update the mapping infrastructure to take full advantage of modern technology and dramatically improve the accuracy of height measurements. To fully realize the billions of dollars in benefits that would come through moving to the modernized NSRS, federal and state and local governments and private sector firms are all going to need to prepare and adapt their procedures and workflows. So our program, GPS on Benchmarks, harnesses the power of partnerships across the country to move us all along the path toward realizing the benefits of the modernized NSRS.
And Greg you had asked too like what can we do locally? When should states be involved? I just wanted to say that your state can be involved right now by organizing and and Utah is by organizing mark recoveries and updates of passive control status, tying your local control stations to the NSRS. And you can just go out and observe like if you can get two hours that’s great, four hours is going to be even better data for us, GPS sessions on your marks. You can run RTN check stations to get updated coordinates on your marks in your areas. And then finally by blue booking and publishing your data with NGS your state then can be better prepared because your your local control is going to be more accurate.
So to do this if you want to do this, if you haven’t been involved in a in a GPS on Benchmarks campaign in the past, we have a prioritized list of survey marks in each state across the country where new data would really help us. So I that information will be in the notes and please feel free to contact me or go and find out more about that. We have a link where you can click directly on that list of marks in your state and go out and find them. So first you search for it. You get your your NGS datasheet and your to reach description and you get in your truck and you go out and find it. Maybe you’ve seen it before and you know of it of that site. You find it, you report back about the condition of the mark by taking we we have a little listing on our website of of directional photos to take of the mark. And then if you have access to survey grade GPS equipment then you can just collect some data on those marks. Two to four hours and then share it with NGS. So there’s two steps to it. If you don’t have any GPS equipment just recovering marks and reporting back about the condition also helps. So there’s there’s a lot you can do, especially even citizen scientists if they want to get involved. Mark recovery is a super fun field activity for folks to do.
And we did have a cutoff date to submit GPS on benchmark data for use in the 2022 transformation tool. We moved it to the end of this calendar year. It was a year ago. But I’m Galen Scott who’s our constituent manager said they may even extend it further because we we want to give people a chance if they just heard about this to jump in and help us. So more detailed information and links can be found at the website that we’ll put here on the podcast which is just geodesy.noaa.gov/GPSonBenchmarks. So we hope you’ll be interested in joining us.
Matt Peters: Yeah I’m sure we’ll we’ll get some takers on that. I am curious though, so you’re doing the GPS on Benchmarks and I’m assuming that this is in support of a vertical datum. And I’m wondering how does the terrestrial benchmarks and the GNSS system kind of work together to to produce a new vertical datum?
Lynda Bell: That’s a really good question and that really comes down to our Online Positioning User Service or OPUS software. And so what happens is and we provide training on the OPUS software as well so that we can help you not only learn how to use it but to be a manager for your company or for your local constituents that you work with. And it’s basically if you think about putting all that data that you just talked about Matt like into the hopper, like into a hopper. And that hopper is all the all the transformation equations that our geodesists at headquarters are writing in our software code. And that comes in and then you create something called a session. And that session has all the marks that you surveyed in it, all your GNSS data. And then you have what are called CORS stations that are in your area. And I know you guys are familiar with those but for some of the listeners if you don’t know what a CORS is, it’s a Continuously Operating Reference System or station. We have a grouping of them all over the United States. There’s a good handful of them in every state. They are generally built and managed by local constituents, often our departments of transportation. And once the data is broadcast to NGS then we ingest it and we provide accurate positions with those continuously operating reference stations. So you’ve got 24/7, 365 days a week at those stations all across your state, all across the country. And we use those to pin down your session of data that you input. So once you lock those down which we are pretty comfortable and accurately knowing the behavior of those stations, then we solve the solution with all of your incoming data that was in the hopper with those CORS stations as the underpinning for the reference system and we give you accurate positions on the other side. So it’s kind of like magic in a way. A lot of people do it with commercial software these days, all the time just click and point and get your positions. But we’re trying to really work on educating the community to help everyone understand what’s behind the scenes, who is Oz behind the screen on all of this so that we can all be part of the pieces and parts we all can be part of in preparing for this more accurate reference system.
Matt Peters: Yeah. Are there are there other programs that states should be involved in?
Lynda Bell: Absolutely, yes. We have many. We really depend on the strength of our users to build the modernized NSRS. So the GPS on Benchmarks that we just talked about is one program states can be involved with. You can publish your data with NGS through OPUS. Again on our website we’ve got training webinars all kinds of cool things where you can learn more about that if you’ve never used OPUS. And you can also submit to the State Plane Coordinate System calls for proposals. So we talked about that earlier in the broadcast as well.
We have a really really active and and well well put together education outreach program at NGS. So if you want further training on our products and services, if you want to find out more about how you can get involved to help strengthen the modernized NSRS then you can contact your NGS Geodetic Coordinator at your state level or your Regional Coordinator Advisor which is me. So in Utah your State Geodetic Coordinator is right there at UGRC, Sean Fernandez. And he works at the just to give UGRC a a shout out, it’s the Utah Geospatial Resource Center and it’s the state of Utah’s map technology coordination office and they’re the fine folks hosting us today. And then I’m your federal regional advisor and I also serve the states of Arizona and New Mexico. So between Sean and myself if you’re in Utah reach out to us. Go on the website that we’re going to provide as well in the notes and we’ve got trainers and teachers and folks to help you with anything you might be interested in.
Greg Bunce: So NGS is tucked under NOAA. Can you explain why that’s the case or why that’s a good fit, Lynda?
Lynda Bell: Yeah, that’s a good question Greg. And you know I proudly have my NOAA patch on my hat and and my sticker on my GOV and all of that. And people say, you know, what and here I am in the Southwest. So people say, “Well what and here I am in the Southwest. So people say, well what’s NOAA doing out here?” And I got that same thing when I worked for NASA and told them that I was an earth scientist they would say, “Why is an earth scientist at NASA?” So the the short answer is that a lot of these big agencies in our country are really kind of the umbrella over all of us that are doing specific things inside of it. So NGS is actually within NOAA’s line office which is called the National Ocean Service. And there’s actually seven programs and two staff offices inside of that. Everything from CO-OPS, the National Center for Coastal Ocean Science, us, the National Geodetic Survey, Office for Coastal Management, Office of Coast Survey, IOOS. And so all of that sounds pretty ocean heavy but we talked a minute ago in the broadcast about this idea of positioning and why NGS focuses on that. So NGS and the National Ocean Service are then under the broad far-reaching service of NOAA. Which again out and about in public people don’t always know what that means. They’ll think NOAA is that a guy’s name? What does that stand for? They or is it Noah like Noah’s Ark? So actually what N-O-A-A stands for is the National Oceanic and Atmospheric Administration. And we’re within the US Department of Commerce.
So inside of NOAA we have um this I think a lot of people know about NOAA satellites because we think about our weather right? So NOAA’s satellite service is called the National Environmental Satellite Data and Information Service or NESDIS. And it’s what’s providing that secure and timely access to all the global environmental data and information from satellites and other sources that we take for granted and use every day to promote and protect the nation’s security, environment, economy, and quality of life. NOAA’s mission is to understand and predict changes in climate, weather, oceans, coasts, and share that knowledge and information with others. To conserve and to manage coastal and marine ecosystems and resources as the nation’s authoritative environmental intelligence agency. So how does NGS fit inside of that? Well we might need to think a minute about the earth. And we often think of the earth as just this round smooth globe like we see in pictures. But in reality its shape and surface are very complex. And this complexity provides challenges when trying to determine the latitude, longitude or elevation of a point on the earth’s surface. And that point could be the surface of the ocean, of an ice mass, the bottom of the ocean, a land mass. It could be all kinds of different landscape everything from a marsh to hard rock at the top of a mountaintop to shifting sands on a beach. If we’re trying to determine those points accurately we have to figure all of this out. And how we do that is we put this inside of something called geodesy. And that is the science of geodesy and it’s really its own branch of science now. When I was in school as a young geophysicist we had classes on geodesy but it wasn’t a major yet. Now it’s a major all the way up to a PhD. And what geodesy is is the science of accurately measuring and understanding three fundamental properties of the earth: its geometric shape, its orientation in space, and its gravity field. As well as all the changes of those properties with time. So at NOAA under the National Ocean Service, geodesy is the business of the National Geodetic Survey. So again we’re sort of an underpinning under all of that great environmental science work that’s being done in NOAA.
Matt Peters: So you know now that you kind of mentioned that it kind of uh kind of pushes me around a bit and I remember, hey hey we’re only just one country on the earth. And so when I think about all the things you’re talking about and the underpinnings of the planet, what what’s the coordination with other uh countries?
Lynda Bell: That’s a really good question Matt and I’m really proud to report on what we do um outside of the US. So of course thinking about all this work we’ve talked about today we’re very very busy just right here in our own country and then certainly at the state and local level all of you are very busy as well. But NGS because we’re under the hat of NOAA and the Department of Commerce, collaboration with other countries is very very important. So we are very active and NGS geodesists travel the world and we collaborate with fellow scientists and policy makers. NGS actually works with the United Nations. We work um we have several of our top geodesists who sit on the United Nations Geospatial Sessions, the International Global Navigation Satellite System Service, the United Nations Pacific Geospatial Conference, the Canadian Geodetic Conference, and Cuba’s National Office of Hydrography and Geodesy. So those are some of our like everyday roles that we we hold those positions in those conferences and in those committees so that we have a voice on the international stage when these discussions come up. And you can imagine at the international level again because this is this is about security and positioning, that can underpin everything from national international security during wartime, it can underpin um discussions on climate change. So you can imagine some of those discussions at the UN um the detail and depth that they go into. And it’s very very important to have international um geodetic reference frames that we all can talk about on the same page. And NGS is a really big part of advising on on the international um reference frames.
So just um just a quick shout out just to show you how active we are. Just in the last 30 days um our Chief Geodesist um and a US representative of one of our advisors just attended the 12th session of the United Nations Committee of Experts on Global Geospatial Information Management. These kinds of participations strengthen relationships with other nations as well as addressing mutual interest. The participants at this meeting agreed that there’s a need right now for enhanced technical relationships between the marine and terrestrial domains to better measure and understand physical height interactions between land and water especially during these dramatic changes that were seeing with sea level change and climate change. Um so this also bolsters our relationships with federal partners too and within NOAA. And particularly we’re um missioned from the Office of Coast Survey to to interact internationally.
Um I just talked a little bit about um the the really cool survey going on right now in the Great Lakes. We’re working with Canada, that’s an international relationship there with our Canadian partners to update the International Great Lakes Datum. And then more specifically to sort of what we were talking about earlier of modernizing the NSRS, this I think is really important because I’ve heard people ask me this a lot at conferences or in phone calls is are these new changes going to be in our equipment that we use out in the field every day? So NGS just hosted representatives from leading global survey equipment manufacturers and geospatial software from all over the world to discuss those recent changes and future developments for NGS’s OPUS. So we’re right now working with sharing our algorithms um with the commercial sector so that surveyors and engineers when they’re out in the field will have this these new algorithms embedded in their instruments and in their software. So this is a really important meeting and it was part of an ongoing strategy to really engage the geospatial community on OPUS and ensure developers build those tools to help the constituents reap the benefits of that modernized system.
So right now one of the very specific things that I’m going to be talking about this in some of the conferences I’ll be touring in this next year, we actually have set up a more comprehensive standard file format. So surveyors can then input into that hopper Matt we talked about earlier um GNSS measurements as well as leveling, angle, distance, azimuth and relative gravity measurements. So these are the kinds of things that we’re doing at the international level and I think it it really enhances um and improves our work at the national and local level as well.
Greg Bunce: It’s it’s like the way you you have an analogy for it. I think um that’s the best way that we can wrap our heads around it, the folks who use it, you know, less often than you do. The analogies help. Your colleague Brian Shaw from the Rocky Mountain, yes um he he’s got a pretty good analogy as well and I and I like your one with directions. I I recall him describing it essentially like as your kids are growing up you mark the lines on the wall and you keep marking them as they grow and you get all these lines on the wall for how tall they are. But the datum really is the floor. And if you put carpet in or if you take the carpet out or put hardwood in, now you’ve just changed the reference point and the datum and the measurements and the markings are not consistent anymore.
So the current one is is NAD 83, correct? And you and and you folks are working toward um replacing NAD 83?
Lynda Bell: Yes. Yes, we are. And so um we’re going to be including uh Greg and I talked about this some specific notes that give more detail where people can really come in and really read more about what we’re doing. And so I’m going to make sure that I don’t speak to too much of that data, but I do want to make sure that you know that it’ll be there for you to read in depth more about this question that Greg just answered.
But in general um what’s going on with the new datum is that we’re replacing the official NAD 83 and NAVD 88 that’s currently the underpinning of the National Spatial Reference System. And although they’re still the official geometric and geopotential datums of the NSRS, they’ve been identified as having shortcomings, sort of like what Greg was just talking about putting the carpet in and removing it. And those shortcomings we feel at NGS are best addressed through defining new horizontal and vertical datums. So these new definitions are going to address the fact that here’s what those shortcomings are. Right now NAD 83 is non-geocentric by about 2.2 meters and the vertical 88 is both biased and tilted relative to the best global geoid models we have today. So why we have these issues just derives from the fact that both datums were defined initially using terrestrial surveying techniques at passive geodetic marks. Now we have these more modern techniques of observing the earth’s surface from space. That network of historic survey marks just age and deteriorate over time. Both through unchecked physical movement, we could have subsidence, we could have construction that disturbs the movement, we could be in a tectonically active area. Sometimes they’re just simply removed um and nobody knows what to do, you know, that they’re supposed to like try to um resurvey that mark and tie it back into the database. Sometimes they call us at NGS and we help them with that process. Sometimes they just don’t know and they’re just removed. And so if that was the underpinning of the network of understanding those datums and we’re losing those survey marks or they’re deteriorating, then we’ve got the carpet problem again. And something’s moving that we don’t understand in that datum. So updating with all the new space geodetic data that we’ve been collecting over the last 20 years is really what is allowing us to modernize this datum.
So we’re going to replace all three NAD 83 frames and all vertical datums with four new terrestrial reference frames and a geopotential datum. The new reference frames are going to rely primarily on GPS or the Global Navigation Satellite System it’s within. So if you’ve been part of GPS for a while, we started out where all we had was a suite I think when I first started surveying for NASA we had 20 maybe satellites I think that we could see. They were just GPS. Now we have we have GPS satellites from all over the world and that is a larger array called the Global Navigation Satellite System. That just gives us more satellites in the sky, more sky coverage, and a better chance to to capture at our receivers when we’re surveying much more accurate points. So we will be um using primarily that data as well as the GRAV-D gravimetric um data that I was talking about that’s being flown across the country right now. These new reference frames will be easier to access and maintain than the current one, which relies on these old physical survey marks that deteriorate over time. So we’re going to call that new reference system the Modernized NSRS. The release of the Modernized NSRS was initially projected to be this year and so it will be named the NSRS 2022 or the SPCS 2022 for State Plane, but the actual projected release date for both is is now looking to be sometime in 2025.
Matt Peters: I, you know, there was just to take a little side note, can you tell me quick what the GRAV-D survey is?
Lynda Bell: Yes, I know I was throwing a lot of acronyms out quickly. So spelled out that is the Gravity for the Redefinition of the American Vertical Datum Project. GRAV-D. And so we’re flying gravity surveys from airplanes across the country. And we’re ground truthing them too with surveys that are done primarily at airports across the US. So we’ve we’ve had several being flown right here in our region of Utah, New Mexico and Arizona just since I’ve been on-boarded. I think there’s been two big airborne GRAV-D surveys flown. So we’re really, that is really what we’re using to redefine the vertical.
Matt Peters: Is it some kind of a LIDAR or what?
Lynda Bell: It’s a gravimeter. Basically, and I think it’s both LIDAR and gravimeter being flown on a plane and measuring as it flies. And then there’s ground-based gravimeters as well. So there’s, I think like I said, most of the ground-based survey points are at airports. And they’re then just ground truthing the flown data. And you know, I’m not sure everything that’s flown from that plane, it could be that we have a combination of data coming in from anything orthometric and all kinds of cool stuff. LIDAR as well.
Matt Peters: So all this, all these things you’re speaking of, what type of educational and experience background did you have?
Lynda Bell: Well, I’ve been at this for a little while and I ended up in geodesy because I started out with a degree in geophysics from Virginia Tech. And the story, can I tell a story, is that okay?
Matt Peters: Sure, sure, sure.
Lynda Bell: Okay. So the very untechnical, unglamorous way that I got my first job, which was at NASA, was I was a sophomore undergraduate in geophysics at Virginia Tech and I had my Virginia Tech sweatshirt on. And I rented a canoe, I was a lifeguard at a campground at a state park in Maryland. And I didn’t know that the person in the family that I was renting a canoe to was a NASA engineer. And he was from UVA and I was, you know, just a young Virginia Tech undergrad. And he teased me about what school I went to because UVA and Tech were rivals and still are. And he said, “What are you studying?” And I told him Geophysics. He said, “That is really interesting. What kind of classes do you take?” I said, “Oh, lots of physics and lots of mathematics and advanced math and I have a minor in geology and a major in geophysics and I’m doing Fourier analysis.” And he said, “All of that as an undergrad?” I said, “Yeah, it’s really hard.” And he said, “You know what, we have an internship program we’re starting up at NASA Goddard for students with backgrounds like yours if you’re interested in it. Here’s my colleague’s name and number.” So I, you know, I just very nervously went home and told my folks about it and they were like, “Oh my gosh, are you kidding? Get in touch with them right away.” So I did and I interviewed and got an internship at NASA Goddard after my sophomore year at undergrad.
And I worked for the Crustal Dynamics Project and the Geodynamics Branch of NASA Goddard. And I worked mostly with radio astronomers who were using VLBI or Very Long Baseline Interferometry, which are those big dishes like you see in the movie Contact with Jodie Foster at the VLBA. And we were just starting to, they had really started to obtain some of the first real measurements of crustal motion when I was an intern. And most of them though were looking at the sky and I and my bosses who were people from like MIT and just these amazing, brilliant, brilliant people said, “We’re going to try to understand what these measurements you’re taking from quasars in deep space are showing us on the earth.” And lo and behold we were seeing as we analyzed the data vectors moving in the directions of plate motion. So I was very, very lucky that just as an intern wide-eyed studying under the masters I got a chance to be part of that early work of geodetic surveying.
And I went out later and started working with GPS and we did footprint networks around the VLBI network. We started working in Alaska studying plate motion there, seismic prediction across the San Andreas Fault in California. So that was really neat to get to be part of that work coming back around later in graduate school, working again supported by NASA but through grants in academia at that time. And so that was my educational path. And then I’ve gotten a chance to work also for the National Park Service when I was in grad school as the Sea Level Specialist improving water level monitoring in US ocean and coastal national parks. I worked a little bit in between all of that grad school and work as an adjunct prof and a curriculum developer for a couple of schools, University of Maryland, a couple of schools back East. And that that gave me some chops on teaching and and how to develop training materials and things, part of which is part of my job now. And now I’m serving as your Southwest Regional Advisor and I’m a full-time civil servant for the US Department of Commerce.
Matt Peters: Wow. You’re making me tired.
Lynda Bell: It was a long path but it was interesting. It really I have to say that the path for me was just driven by curiosity. I was working with brilliant scientists from the very beginning and they taught me to be curious and think outside the box and and always look for the next question to ask. And when I then became a science teacher in college classrooms, that really is what I taught my students, that science really is inquiry. And if we’re doing good science, one question should just answer or lead to another question, not an answer. So I really think I have my early mentors to thank for that that dream. Yeah.
Matt Peters: Yeah. There was one thing I I kind of wondered about with that, you know when when you talked about how you met the gentleman, you know with the canoe. I I can’t tell you how many stories or how often that same kind of thing has played out where you sit down somewhere, have a drink with someone, your paths cross, the future blooms. Yeah, it’s pretty crazy.
Greg Bunce: And I think it’s just staying curious. I think that that’s the key there for me as well. And I and I like to I like that point that you made.
I’m also curious about so you mentioned terrestrial a couple times early on. A lot of the the some of the original datums were all you know based on terrestrial stuff. So I’m thinking of benchmarks and I’m thinking of monuments. And we’ve heard of something called the GPS on Benchmarks and and how some of us get involved in that. Are those referring back to the terrestrial benchmarks and kind of GPSing those? Can you talk a bit about that program?
Lynda Bell: Yeah, most definitely Greg. And that is exactly what it is. By definition, we call it our GPS on Benchmarks or GPS on BM program and it’s just a crowdsourced data collection program that helps your community prepare for the modernization of the NSRS. It’s a little bit like geocaching really for folks that like to go out for fun. A lot of times we have retired surveyors help us, community groups, scout groups will go out, young students who are just training on surveying. It doesn’t you don’t have to be currently employed as a professional to help us with this. But the idea of it is to help us increase our knowledge of geodetic positioning on these these benchmarks in your area.
So for the last 200 years actually, the nation’s foundational mapping infrastructure has relied on hundreds of thousands of survey marks set in the ground across the country. So in 2007 NGS embarked on a decades-long endeavor to update the mapping infrastructure to take full advantage of modern technology and dramatically improve the accuracy of height measurements. To fully realize the billions of dollars in benefits that would come through moving to the modernized NSRS, federal and state and local governments and private sector firms are all going to need to prepare and adapt their procedures and workflows. So our program, GPS on Benchmarks, harnesses the power of partnerships across the country to move us all along the path toward realizing the benefits of the modernized NSRS.
And Greg you had asked too like what can we do locally? When should states be involved? I just wanted to say that your state can be involved right now by organizing and and Utah is by organizing mark recoveries and updates of passive control status, tying your local control stations to the NSRS. And you can just go out and observe like if you can get two hours that’s great, four hours is going to be even better data for us, GPS sessions on your marks. You can run RTN check stations to get updated coordinates on your marks in your areas. And then finally by blue booking and publishing your data with NGS your state then can be better prepared because your your local control is going to be more accurate.
So to do this if you want to do this, if you haven’t been involved in a in a GPS on Benchmarks campaign in the past, we have a prioritized list of survey marks in each state across the country where new data would really help us. So I that information will be in the notes and please feel free to contact me or go and find out more about that. We have a link where you can click directly on that list of marks in your state and go out and find them. So first you search for it. You get your your NGS datasheet and your to reach description and you get in your truck and you go out and find it. Maybe you’ve seen it before and you know of it of that site. You find it, you report back about the condition of the mark by taking we we have a little listing on our website of of directional photos to take of the mark. And then if you have access to survey grade GPS equipment then you can just collect some data on those marks. Two to four hours and then share it with NGS. So there’s two steps to it. If you don’t have any GPS equipment just recovering marks and reporting back about the condition also helps. So there’s there’s a lot you can do, especially even citizen scientists if they want to get involved. Mark recovery is a super fun field activity for folks to do.
And we did have a cutoff date to submit GPS on benchmark data for use in the 2022 transformation tool. We moved it to the end of this calendar year. It was a year ago. But I’m Galen Scott who’s our constituent manager said they may even extend it further because we we want to give people a chance if they just heard about this to jump in and help us. So more detailed information and links can be found at the website that we’ll put here on the podcast which is just geodesy.noaa.gov/GPSonBenchmarks. So we hope you’ll be interested in joining us.
Matt Peters: Yeah I’m sure we’ll we’ll get some takers on that. I am curious though, so you’re doing the GPS on Benchmarks and I’m assuming that this is in support of a vertical datum. And I’m wondering how does the terrestrial benchmarks and the GNSS system kind of work together to to produce a new vertical datum?
Lynda Bell: That’s a really good question and that really comes down to our Online Positioning User Service or OPUS software. And so what happens is and we provide training on the OPUS software as well so that we can help you not only learn how to use it but to be a manager for your company or for your local constituents that you work with. And it’s basically if you think about putting all that data that you just talked about Matt like into the hopper, like into a hopper. And that hopper is all the all the transformation equations that our geodesists at headquarters are writing in our software code. And that comes in and then you create something called a session. And that session has all the marks that you surveyed in it, all your GNSS data. And then you have what are called CORS stations that are in your area. And I know you guys are familiar with those but for some of the listeners if you don’t know what a CORS is, it’s a Continuously Operating Reference System or station. We have a grouping of them all over the United States. There’s a good handful of them in every state. They are generally built and managed by local constituents, often our departments of transportation. And once the data is broadcast to NGS then we ingest it and we provide accurate positions with those continuously operating reference stations. So you’ve got 24/7, 365 days a week at those stations all across your state, all across the country. And we use those to pin down your session of data that you input. So once you lock those down which we are pretty comfortable and accurately knowing the behavior of those stations, then we solve the solution with all of your incoming data that was in the hopper with those CORS stations as the underpinning for the reference system and we give you accurate positions on the other side. So it’s kind of like magic in a way. A lot of people do it with commercial software these days, all the time just click and point and get your positions. But we’re trying to really work on educating the community to help everyone understand what’s behind the scenes, who is Oz behind the screen on all of this so that we can all be part of the pieces and parts we all can be part of in preparing for this more accurate reference system.
Matt Peters: Yeah. Are there are there other programs that states should be involved in?
Lynda Bell: Absolutely, yes. We have many. We really depend on the strength of our users to build the modernized NSRS. So the GPS on Benchmarks that we just talked about is one program states can be involved with. You can publish your data with NGS through OPUS. Again on our website we’ve got training webinars all kinds of cool things where you can learn more about that if you’ve never used OPUS. And you can also submit to the State Plane Coordinate System calls for proposals. So we talked about that earlier in the broadcast as well.
We have a really really active and and well well put together education outreach program at NGS. So if you want further training on our products and services, if you want to find out more about how you can get involved to help strengthen the modernized NSRS then you can contact your NGS Geodetic Coordinator at your state level or your Regional Coordinator Advisor which is me. So in Utah your State Geodetic Coordinator is right there at UGRC, Sean Fernandez. And he works at the just to give UGRC a a shout out, it’s the Utah Geospatial Resource Center and it’s the state of Utah’s map technology coordination office and they’re the fine folks hosting us today. And then I’m your federal regional advisor and I also serve the states of Arizona and New Mexico. So between Sean and myself if you’re in Utah reach out to us. Go on the website that we’re going to provide as well in the notes and we’ve got trainers and teachers and folks to help you with anything you might be interested in.
Greg Bunce: So NGS is tucked under NOAA. Can you explain why that’s the case or why that’s a good fit, Lynda?
Lynda Bell: Yeah, that’s a good question Greg. And you know I proudly have my NOAA patch on my hat and and my sticker on my GOV and all of that. And people say, you know, what and here I am in the Southwest. So people say, “Well what and here I am in the Southwest. So people say, well what’s NOAA doing out here?” And I got that same thing when I worked for NASA and told them that I was an earth scientist they would say, “Why is an earth scientist at NASA?” So the the short answer is that a lot of these big agencies in our country are really kind of the umbrella over all of us that are doing specific things inside of it. So NGS is actually within NOAA’s line office which is called the National Ocean Service. And there’s actually seven programs and two staff offices inside of that. Everything from CO-OPS, the National Center for Coastal Ocean Science, us, the National Geodetic Survey, Office for Coastal Management, Office of Coast Survey, IOOS. And so all of that sounds pretty ocean heavy but we talked a minute ago in the broadcast about this idea of positioning and why NGS focuses on that. So NGS and the National Ocean Service are then under the broad far-reaching service of NOAA. Which again out and about in public people don’t always know what that means. They’ll think NOAA is that a guy’s name? What does that stand for? They or is it Noah like Noah’s Ark? So actually what N-O-A-A stands for is the National Oceanic and Atmospheric Administration. And we’re within the US Department of Commerce.
So inside of NOAA we have um this I think a lot of people know about NOAA satellites because we think about our weather right? So NOAA’s satellite service is called the National Environmental Satellite Data and Information Service or NESDIS. And it’s what’s providing that secure and timely access to all the global environmental data and information from satellites and other sources that we take for granted and use every day to promote and protect the nation’s security, environment, economy, and quality of life. NOAA’s mission is to understand and predict changes in climate, weather, oceans, coasts, and share that knowledge and information with others. To conserve and to manage coastal and marine ecosystems and resources as the nation’s authoritative environmental intelligence agency. So how does NGS fit inside of that? Well we might need to think a minute about the earth. And we often think of the earth as just this round smooth globe like we see in pictures. But in reality its shape and surface are very complex. And this complexity provides challenges when trying to determine the latitude, longitude or elevation of a point on the earth’s surface. And that point could be the surface of the ocean, of an ice mass, the bottom of the ocean, a land mass. It could be all kinds of different landscape everything from a marsh to hard rock at the top of a mountaintop to shifting sands on a beach. If we’re trying to determine those points accurately we have to figure all of this out. And how we do that is we put this inside of something called geodesy. And that is the science of geodesy and it’s really its own branch of science now. When I was in school as a young geophysicist we had classes on geodesy but it wasn’t a major yet. Now it’s a major all the way up to a PhD. And what geodesy is is the science of accurately measuring and understanding three fundamental properties of the earth: its geometric shape, its orientation in space, and its gravity field. As well as all the changes of those properties with time. So at NOAA under the National Ocean Service, geodesy is the business of the National Geodetic Survey. So again we’re sort of an underpinning under all of that great environmental science work that’s being done in NOAA.
Matt Peters: So you know now that you kind of mentioned that it kind of uh kind of pushes me around a bit and I remember, hey hey we’re only just one country on the earth. And so when I think about all the things you’re talking about and the underpinnings of the planet, what what’s the coordination with other uh countries?
Lynda Bell: That’s a really good question Matt and I’m really proud to report on what we do um outside of the US. So of course thinking about all this work we’ve talked about today we’re very very busy just right here in our own country and then certainly at the state and local level all of you are very busy as well. But NGS because we’re under the hat of NOAA and the Department of Commerce, collaboration with other countries is very very important. So we are very active and NGS geodesists travel the world and we collaborate with fellow scientists and policy makers. NGS actually works with the United Nations. We work um we have several of our top geodesists who sit on the United Nations Geospatial Sessions, the International Global Navigation Satellite System Service, the United Nations Pacific Geospatial Conference, the Canadian Geodetic Conference, and Cuba’s National Office of Hydrography and Geodesy. So those are some of our like everyday roles that we we hold those positions in those conferences and in those committees so that we have a voice on the international stage when these discussions come up. And you can imagine at the international level again because this is this is about security and positioning, that can underpin everything from national international security during wartime, it can underpin um discussions on climate change. So you can imagine some of those discussions at the UN um the detail and depth that they go into. And it’s very very important to have international um geodetic reference frames that we all can talk about on the same page. And NGS is a really big part of advising on on the international um reference frames.
So just um just a quick shout out just to show you how active we are. Just in the last 30 days um our Chief Geodesist um and a US representative of one of our advisors just attended the 12th session of the United Nations Committee of Experts on Global Geospatial Information Management. These kinds of participations strengthen relationships with other nations as well as addressing mutual interest. The participants at this meeting agreed that there’s a need right now for enhanced technical relationships between the marine and terrestrial domains to better measure and understand physical height interactions between land and water especially during these dramatic changes that were seeing with sea level change and climate change. Um so this also bolsters our relationships with federal partners too and within NOAA. And particularly we’re um missioned from the Office of Coast Survey to to interact internationally.
Um I just talked a little bit about um the the really cool survey going on right now in the Great Lakes. We’re working with Canada, that’s an international relationship there with our Canadian partners to update the International Great Lakes Datum. And then more specifically to sort of what we were talking about earlier of modernizing the NSRS, this I think is really important because I’ve heard people ask me this a lot at conferences or in phone calls is are these new changes going to be in our equipment that we use out in the field every day? So NGS just hosted representatives from leading global survey equipment manufacturers and geospatial software from all over the world to discuss those recent changes and future developments for NGS’s OPUS. So we’re right now working with sharing our algorithms um with the commercial sector so that surveyors and engineers when they’re out in the field will have this these new algorithms embedded in their instruments and in their software. So this is a really important meeting and it was part of an ongoing strategy to really engage the geospatial community on OPUS and ensure developers build those tools to help the constituents reap the benefits of that modernized system.
So right now one of the very specific things that I’m going to be talking about this in some of the conferences I’ll be touring in this next year, we actually have set up a more comprehensive standard file format. So surveyors can then input into that hopper Matt we talked about earlier um GNSS measurements as well as leveling, angle, distance, azimuth and relative gravity measurements. So these are the kinds of things that we’re doing at the international level and I think it it really enhances um and improves our work at the national and local level as well.
Greg Bunce: It’s it’s like the way you you have an analogy for it. I think um that’s the best way that we can wrap our heads around it, the folks who use it, you know, less often than you do. The analogies help. Your colleague Brian Shaw from the Rocky Mountain, yes um he he’s got a pretty good analogy as well and I and I like your one with directions. I I recall him describing it essentially like as your kids are growing up you mark the lines on the wall and you keep marking them as they grow and you get all these lines on the wall for how tall they are. But the datum really is the floor. And if you put carpet in or if you take the carpet out or put hardwood in, now you’ve just changed the reference point and the datum and the measurements and the markings are not consistent anymore.
So the current one is is NAD 83, correct? And you and and you folks are working toward um replacing NAD 83?
Lynda Bell: Yes. Yes, we are. And so um we’re going to be including uh Greg and I talked about this some specific notes that give more detail where people can really come in and really read more about what we’re doing. And so I’m going to make sure that I don’t speak to too much of that data, but I do want to make sure that you know that it’ll be there for you to read in depth more about this question that Greg just answered.
But in general um what’s going on with the new datum is that we’re replacing the official NAD 83 and NAVD 88 that’s currently the underpinning of the National Spatial Reference System. And although they’re still the official geometric and geopotential datums of the NSRS, they’ve been identified as having shortcomings, sort of like what Greg was just talking about putting the carpet in and removing it. And those shortcomings we feel at NGS are best addressed through defining new horizontal and vertical datums. So these new definitions are going to address the fact that here’s what those shortcomings are. Right now NAD 83 is non-geocentric by about 2.2 meters and the vertical 88 is both biased and tilted relative to the best global geoid models we have today. So why we have these issues just derives from the fact that both datums were defined initially using terrestrial surveying techniques at passive geodetic marks. Now we have these more modern techniques of observing the earth’s surface from space. That network of historic survey marks just age and deteriorate over time. Both through unchecked physical movement, we could have subsidence, we could have construction that disturbs the movement, we could be in a tectonically active area. Sometimes they’re just simply removed um and nobody knows what to do, you know, that they’re supposed to like try to um resurvey that mark and tie it back into the database. Sometimes they call us at NGS and we help them with that process. Sometimes they just don’t know and they’re just removed. And so if that was the underpinning of the network of understanding those datums and we’re losing those survey marks or they’re deteriorating, then we’ve got the carpet problem again. And something’s moving that we don’t understand in that datum. So updating with all the new space geodetic data that we’ve been collecting over the last 20 years is really what is allowing us to modernize this datum.
So we’re going to replace all three NAD 83 frames and all vertical datums with four new terrestrial reference frames and a geopotential datum. The new reference frames are going to rely primarily on GPS or the Global Navigation Satellite System it’s within. So if you’ve been part of GPS for a while, we started out where all we had was a suite I think when I first started surveying for NASA we had 20 maybe satellites I think that we could see. They were just GPS. Now we have we have GPS satellites from all over the world and that is a larger array called the Global Navigation Satellite System. That just gives us more satellites in the sky, more sky coverage, and a better chance to to capture at our receivers when we’re surveying much more accurate points. So we will be um using primarily that data as well as the GRAV-D gravimetric um data that I was talking about that’s being flown across the country right now. These new reference frames will be easier to access and maintain than the current one, which relies on these old physical survey marks that deteriorate over time. So we’re going to call that new reference system the Modernized NSRS. The release of the Modernized NSRS was initially projected to be this year and so it will be named the NSRS 2022 or the SPCS 2022 for State Plane, but the actual projected release date for both is is now looking to be sometime in 2025.
Matt Peters: I, you know, there was just to take a little side note, can you tell me quick what the GRAV-D survey is?
Lynda Bell: Yes, I know I was throwing a lot of acronyms out quickly. So spelled out that is the Gravity for the Redefinition of the American Vertical Datum Project. GRAV-D. And so we’re flying gravity surveys from airplanes across the country. And we’re ground truthing them too with surveys that are done primarily at airports across the US. So we’ve we’ve had several being flown right here in our region of Utah, New Mexico and Arizona just since I’ve been on-boarded. I think there’s been two big airborne GRAV-D surveys flown. So we’re really, that is really what we’re using to redefine the vertical.
Matt Peters: Is it some kind of a LIDAR or what?
Lynda Bell: It’s a gravimeter. Basically, and I think it’s both LIDAR and gravimeter being flown on a plane and measuring as it flies. And then there’s ground-based gravimeters as well. So there’s, I think like I said, most of the ground-based survey points are at airports. And they’re then just ground truthing the flown data. And you know, I’m not sure everything that’s flown from that plane, it could be that we have a combination of data coming in from anything orthometric and all kinds of cool stuff. LIDAR as well.
Matt Peters: So all this, all these things you’re speaking of, what type of educational and experience background did you have?
Lynda Bell: Well, I’ve been at this for a little while and I ended up in geodesy because I started out with a degree in geophysics from Virginia Tech. And the story, can I tell a story, is that okay?
Matt Peters: Sure, sure, sure.
Lynda Bell: Okay. So the very untechnical, unglamorous way that I got my first job, which was at NASA, was I was a sophomore undergraduate in geophysics at Virginia Tech and I had my Virginia Tech sweatshirt on. And I rented a canoe, I was a lifeguard at a campground at a state park in Maryland. And I didn’t know that the person in the family that I was renting a canoe to was a NASA engineer. And he was from UVA and I was, you know, just a young Virginia Tech undergrad. And he teased me about what school I went to because UVA and Tech were rivals and still are. And he said, “What are you studying?” And I told him Geophysics. He said, “That is really interesting. What kind of classes do you take?” I said, “Oh, lots of physics and lots of mathematics and advanced math and I have a minor in geology and a major in geophysics and I’m doing Fourier analysis.” And he said, “All of that as an undergrad?” I said, “Yeah, it’s really hard.” And he said, “You know what, we have an internship program we’re starting up at NASA Goddard for students with backgrounds like yours if you’re interested in it. Here’s my colleague’s name and number.” So I, you know, I just very nervously went home and told my folks about it and they were like, “Oh my gosh, are you kidding? Get in touch with them right away.” So I did and I interviewed and got an internship at NASA Goddard after my sophomore year at undergrad.
And I worked for the Crustal Dynamics Project and the Geodynamics Branch of NASA Goddard. And I worked mostly with radio astronomers who were using VLBI or Very Long Baseline Interferometry, which are those big dishes like you see in the movie Contact with Jodie Foster at the VLBA. And we were just starting to, they had really started to obtain some of the first real measurements of crustal motion when I was an intern. And most of them though were looking at the sky and I and my bosses who were people from like MIT and just these amazing, brilliant, brilliant people said, “We’re going to try to understand what these measurements you’re taking from quasars in deep space are showing us on the earth.” And lo and behold we were seeing as we analyzed the data vectors moving in the directions of plate motion. So I was very, very lucky that just as an intern wide-eyed studying under the masters I got a chance to be part of that early work of geodetic surveying.
And I went out later and started working with GPS and we did footprint networks around the VLBI network. We started working in Alaska studying plate motion there, seismic prediction across the San Andreas Fault in California. So that was really neat to get to be part of that work coming back around later in graduate school, working again supported by NASA but through grants in academia at that time. And so that was my educational path. And then I’ve gotten a chance to work also for the National Park Service when I was in grad school as the Sea Level Specialist improving water level monitoring in US ocean and coastal national parks. I worked a little bit in between all of that grad school and work as an adjunct prof and a curriculum developer for a couple of schools, University of Maryland, a couple of schools back East. And that that gave me some chops on teaching and and how to develop training materials and things, part of which is part of my job now. And now I’m serving as your Southwest Regional Advisor and I’m a full-time civil servant for the US Department of Commerce.
Matt Peters: Wow. You’re making me tired.
Lynda Bell: It was a long path but it was interesting. It really I have to say that the path for me was just driven by curiosity. I was working with brilliant scientists from the very beginning and they taught me to be curious and think outside the box and and always look for the next question to ask. And when I then became a science teacher in college classrooms, that really is what I taught my students, that science really is inquiry. And if we’re doing good science, one question should just answer or lead to another question, not an answer. So I really think I have my early mentors to thank for that that dream. Yeah.
Matt Peters: Yeah. There was one thing I I kind of wondered about with that, you know when when you talked about how you met the gentleman, you know with the canoe. I I can’t tell you how many stories or how often that same kind of thing has played out where you sit down somewhere, have a drink with someone, your paths cross, the future blooms. Yeah, it’s pretty crazy.
Greg Bunce: And I think it’s just staying curious. I think that that’s the key there for me as well. And I and I like to I like that point that you made.
I’m also curious about so you mentioned terrestrial a couple times early on. A lot of the the some of the original datums were all you know based on terrestrial stuff. So I’m thinking of benchmarks and I’m thinking of monuments. And we’ve heard of something called the GPS on Benchmarks and and how some of us get involved in that. Are those referring back to the terrestrial benchmarks and kind of GPSing those? Can you talk a bit about that program?
Lynda Bell: Yeah, most definitely Greg. And that is exactly what it is. By definition, we call it our GPS on Benchmarks or GPS on BM program and it’s just a crowdsourced data collection program that helps your community prepare for the modernization of the NSRS. It’s a little bit like geocaching really for folks that like to go out for fun. A lot of times we have retired surveyors help us, community groups, scout groups will go out, young students who are just training on surveying. It doesn’t you don’t have to be currently employed as a professional to help us with this. But the idea of it is to help us increase our knowledge of geodetic positioning on these these benchmarks in your area.
So for the last 200 years actually, the nation’s foundational mapping infrastructure has relied on hundreds of thousands of survey marks set in the ground across the country. So in 2007 NGS embarked on a decades-long endeavor to update the mapping infrastructure to take full advantage of modern technology and dramatically improve the accuracy of height measurements. To fully realize the billions of dollars in benefits that would come through moving to the modernized NSRS, federal and state and local governments and private sector firms are all going to need to prepare and adapt their procedures and workflows. So our program, GPS on Benchmarks, harnesses the power of partnerships across the country to move us all along the path toward realizing the benefits of the modernized NSRS.
And Greg you had asked too like what can we do locally? When should states be involved? I just wanted to say that your state can be involved right now by organizing and and Utah is by organizing mark recoveries and updates of passive control status, tying your local control stations to the NSRS. And you can just go out and observe like if you can get two hours that’s great, four hours is going to be even better data for us, GPS sessions on your marks. You can run RTN check stations to get updated coordinates on your marks in your areas. And then finally by blue booking and publishing your data with NGS your state then can be better prepared because your your local control is going to be more accurate.
So to do this if you want to do this, if you haven’t been involved in a in a GPS on Benchmarks campaign in the past, we have a prioritized list of survey marks in each state across the country where new data would really help us. So I that information will be in the notes and please feel free to contact me or go and find out more about that. We have a link where you can click directly on that list of marks in your state and go out and find them. So first you search for it. You get your your NGS datasheet and your to reach description and you get in your truck and you go out and find it. Maybe you’ve seen it before and you know of it of that site. You find it, you report back about the condition of the mark by taking we we have a little listing on our website of of directional photos to take of the mark. And then if you have access to survey grade GPS equipment then you can just collect some data on those marks. Two to four hours and then share it with NGS. So there’s two steps to it. If you don’t have any GPS equipment just recovering marks and reporting back about the condition also helps. So there’s there’s a lot you can do, especially even citizen scientists if they want to get involved. Mark recovery is a super fun field activity for folks to do.
And we did have a cutoff date to submit GPS on benchmark data for use in the 2022 transformation tool. We moved it to the end of this calendar year. It was a year ago. But I’m Galen Scott who’s our constituent manager said they may even extend it further because we we want to give people a chance if they just heard about this to jump in and help us. So more detailed information and links can be found at the website that we’ll put here on the podcast which is just geodesy.noaa.gov/GPSonBenchmarks. So we hope you’ll be interested in joining us.
Matt Peters: Yeah I’m sure we’ll we’ll get some takers on that. I am curious though, so you’re doing the GPS on Benchmarks and I’m assuming that this is in support of a vertical datum. And I’m wondering how does the terrestrial benchmarks and the GNSS system kind of work together to to produce a new vertical datum?
Lynda Bell: That’s a really good question and that really comes down to our Online Positioning User Service or OPUS software. And so what happens is and we provide training on the OPUS software as well so that we can help you not only learn how to use it but to be a manager for your company or for your local constituents that you work with. And it’s basically if you think about putting all that data that you just talked about Matt like into the hopper, like into a hopper. And that hopper is all the all the transformation equations that our geodesists at headquarters are writing in our software code. And that comes in and then you create something called a session. And that session has all the marks that you surveyed in it, all your GNSS data. And then you have what are called CORS stations that are in your area. And I know you guys are familiar with those but for some of the listeners if you don’t know what a CORS is, it’s a Continuously Operating Reference System or station. We have a grouping of them all over the United States. There’s a good handful of them in every state. They are generally built and managed by local constituents, often our departments of transportation. And once the data is broadcast to NGS then we ingest it and we provide accurate positions with those continuously operating reference stations. So you’ve got 24/7, 365 days a week at those stations all across your state, all across the country. And we use those to pin down your session of data that you input. So once you lock those down which we are pretty comfortable and accurately knowing the behavior of those stations, then we solve the solution with all of your incoming data that was in the hopper with those CORS stations as the underpinning for the reference system and we give you accurate positions on the other side. So it’s kind of like magic in a way. A lot of people do it with commercial software these days, all the time just click and point and get your positions. But we’re trying to really work on educating the community to help everyone understand what’s behind the scenes, who is Oz behind the screen on all of this so that we can all be part of the pieces and parts we all can be part of in preparing for this more accurate reference system.
Matt Peters: Yeah. Are there are there other programs that states should be involved in?
Lynda Bell: Absolutely, yes. We have many. We really depend on the strength of our users to build the modernized NSRS. So the GPS on Benchmarks that we just talked about is one program states can be involved with. You can publish your data with NGS through OPUS. Again on our website we’ve got training webinars all kinds of cool things where you can learn more about that if you’ve never used OPUS. And you can also submit to the State Plane Coordinate System calls for proposals. So we talked about that earlier in the broadcast as well.
We have a really really active and and well well put together education outreach program at NGS. So if you want further training on our products and services, if you want to find out more about how you can get involved to help strengthen the modernized NSRS then you can contact your NGS Geodetic Coordinator at your state level or your Regional Coordinator Advisor which is me. So in Utah your State Geodetic Coordinator is right there at UGRC, Sean Fernandez. And he works at the just to give UGRC a a shout out, it’s the Utah Geospatial Resource Center and it’s the state of Utah’s map technology coordination office and they’re the fine folks hosting us today. And then I’m your federal regional advisor and I also serve the states of Arizona and New Mexico. So between Sean and myself if you’re in Utah reach out to us. Go on the website that we’re going to provide as well in the notes and we’ve got trainers and teachers and folks to help you with anything you might be interested in.
Greg Bunce: So NGS is tucked under NOAA. Can you explain why that’s the case or why that’s a good fit, Lynda?
Lynda Bell: Yeah, that’s a good question Greg. And you know I proudly have my NOAA patch on my hat and and my sticker on my GOV and all of that. And people say, you know, what and here I am in the Southwest. So people say, “Well what and here I am in the Southwest. So people say, well what’s NOAA doing out here?” And I got that same thing when I worked for NASA and told them that I was an earth scientist they would say, “Why is an earth scientist at NASA?” So the the short answer is that a lot of these big agencies in our country are really kind of the umbrella over all of us that are doing specific things inside of it. So NGS is actually within NOAA’s line office which is called the National Ocean Service. And there’s actually seven programs and two staff offices inside of that. Everything from CO-OPS, the National Center for Coastal Ocean Science, us, the National Geodetic Survey, Office for Coastal Management, Office of Coast Survey, IOOS. And so all of that sounds pretty ocean heavy but we talked a minute ago in the broadcast about this idea of positioning and why NGS focuses on that. So NGS and the National Ocean Service are then under the broad far-reaching service of NOAA. Which again out and about in public people don’t always know what that means. They’ll think NOAA is that a guy’s name? What does that stand for? They or is it Noah like Noah’s Ark? So actually what N-O-A-A stands for is the National Oceanic and Atmospheric Administration. And we’re within the US Department of Commerce.
So inside of NOAA we have um this I think a lot of people know about NOAA satellites because we think about our weather right? So NOAA’s satellite service is called the National Environmental Satellite Data and Information Service or NESDIS. And it’s what’s providing that secure and timely access to all the global environmental data and information from satellites and other sources that we take for granted and use every day to promote and protect the nation’s security, environment, economy, and quality of life. NOAA’s mission is to understand and predict changes in climate, weather, oceans, coasts, and share that knowledge and information with others. To conserve and to manage coastal and marine ecosystems and resources as the nation’s authoritative environmental intelligence agency. So how does NGS fit inside of that? Well we might need to think a minute about the earth. And we often think of the earth as just this round smooth globe like we see in pictures. But in reality its shape and surface are very complex. And this complexity provides challenges when trying to determine the latitude, longitude or elevation of a point on the earth’s surface. And that point could be the surface of the ocean, of an ice mass, the bottom of the ocean, a land mass. It could be all kinds of different landscape everything from a marsh to hard rock at the top of a mountaintop to shifting sands on a beach. If we’re trying to determine those points accurately we have to figure all of this out. And how we do that is we put this inside of something called geodesy. And that is the science of geodesy and it’s really its own branch of science now. When I was in school as a young geophysicist we had classes on geodesy but it wasn’t a major yet. Now it’s a major all the way up to a PhD. And what geodesy is is the science of accurately measuring and understanding three fundamental properties of the earth: its geometric shape, its orientation in space, and its gravity field. As well as all the changes of those properties with time. So at NOAA under the National Ocean Service, geodesy is the business of the National Geodetic Survey. So again we’re sort of an underpinning under all of that great environmental science work that’s being done in NOAA.
Matt Peters: So you know now that you kind of mentioned that it kind of uh kind of pushes me around a bit and I remember, hey hey we’re only just one country on the earth. And so when I think about all the things you’re talking about and the underpinnings of the planet, what what’s the coordination with other uh countries?
Lynda Bell: That’s a really good question Matt and I’m really proud to report on what we do um outside of the US. So of course thinking about all this work we’ve talked about today we’re very very busy just right here in our own country and then certainly at the state and local level all of you are very busy as well. But NGS because we’re under the hat of NOAA and the Department of Commerce, collaboration with other countries is very very important. So we are very active and NGS geodesists travel the world and we collaborate with fellow scientists and policy makers. NGS actually works with the United Nations. We work um we have several of our top geodesists who sit on the United Nations Geospatial Sessions, the International Global Navigation Satellite System Service, the United Nations Pacific Geospatial Conference, the Canadian Geodetic Conference, and Cuba’s National Office of Hydrography and Geodesy. So those are some of our like everyday roles that we we hold those positions in those conferences and in those committees so that we have a voice on the international stage when these discussions come up. And you can imagine at the international level again because this is this is about security and positioning, that can underpin everything from national international security during wartime, it can underpin um discussions on climate change. So you can imagine some of those discussions at the UN um the detail and depth that they go into. And it’s very very important to have international um geodetic reference frames that we all can talk about on the same page. And NGS is a really big part of advising on on the international um reference frames.
So just um just a quick shout out just to show you how active we are. Just in the last 30 days um our Chief Geodesist um and a US representative of one of our advisors just attended the 12th session of the United Nations Committee of Experts on Global Geospatial Information Management. These kinds of participations strengthen relationships with other nations as well as addressing mutual interest. The participants at this meeting agreed that there’s a need right now for enhanced technical relationships between the marine and terrestrial domains to better measure and understand physical height interactions between land and water especially during these dramatic changes that were seeing with sea level change and climate change. Um so this also bolsters our relationships with federal partners too and within NOAA. And particularly we’re um missioned from the Office of Coast Survey to to interact internationally.
Um I just talked a little bit about um the the really cool survey going on right now in the Great Lakes. We’re working with Canada, that’s an international relationship there with our Canadian partners to update the International Great Lakes Datum. And then more specifically to sort of what we were talking about earlier of modernizing the NSRS, this I think is really important because I’ve heard people ask me this a lot at conferences or in phone calls is are these new changes going to be in our equipment that we use out in the field every day? So NGS just hosted representatives from leading global survey equipment manufacturers and geospatial software from all over the world to discuss those recent changes and future developments for NGS’s OPUS. So we’re right now working with sharing our algorithms um with the commercial sector so that surveyors and engineers when they’re out in the field will have this these new algorithms embedded in their instruments and in their software. So this is a really important meeting and it was part of an ongoing strategy to really engage the geospatial community on OPUS and ensure developers build those tools to help the constituents reap the benefits of that modernized system.
So right now one of the very specific things that I’m going to be talking about this in some of the conferences I’ll be touring in this next year, we actually have set up a more comprehensive standard file format. So surveyors can then input into that hopper Matt we talked about earlier um GNSS measurements as well as leveling, angle, distance, azimuth and relative gravity measurements. So these are the kinds of things that we’re doing at the international level and I think it it really enhances um and improves our work at the national and local level as well.
Greg Bunce: It’s it’s like the way you you have an analogy for it. I think um that’s the best way that we can wrap our heads around it, the folks who use it, you know, less often than you do. The analogies help. Your colleague Brian Shaw from the Rocky Mountain, yes um he he’s got a pretty good analogy as well and I and I like your one with directions. I I recall him describing it essentially like as your kids are growing up you mark the lines on the wall and you keep marking them as they grow and you get all these lines on the wall for how tall they are. But the datum really is the floor. And if you put carpet in or if you take the carpet out or put hardwood in, now you’ve just changed the reference point and the datum and the measurements and the markings are not consistent anymore.
So the current one is is NAD 83, correct? And you and and you folks are working toward um replacing NAD 83?
Lynda Bell: Yes. Yes, we are. And so um we’re going to be including uh Greg and I talked about this some specific notes that give more detail where people can really come in and really read more about what we’re doing. And so I’m going to make sure that I don’t speak to too much of that data, but I do want to make sure that you know that it’ll be there for you to read in depth more about this question that Greg just answered.
But in general um what’s going on with the new datum is that we’re replacing the official NAD 83 and NAVD 88 that’s currently the underpinning of the National Spatial Reference System. And although they’re still the official geometric and geopotential datums of the NSRS, they’ve been identified as having shortcomings, sort of like what Greg was just talking about putting the carpet in and removing it. And those shortcomings we feel at NGS are best addressed through defining new horizontal and vertical datums. So these new definitions are going to address the fact that here’s what those shortcomings are. Right now NAD 83 is non-geocentric by about 2.2 meters and the vertical 88 is both biased and tilted relative to the best global geoid models we have today. So why we have these issues just derives from the fact that both datums were defined initially using terrestrial surveying techniques at passive geodetic marks. Now we have these more modern techniques of observing the earth’s surface from space. That network of historic survey marks just age and deteriorate over time. Both through unchecked physical movement, we could have subsidence, we could have construction that disturbs the movement, we could be in a tectonically active area. Sometimes they’re just simply removed um and nobody knows what to do, you know, that they’re supposed to like try to um resurvey that mark and tie it back into the database. Sometimes they call us at NGS and we help them with that process. Sometimes they just don’t know and they’re just removed. And so if that was the underpinning of the network of understanding those datums and we’re losing those survey marks or they’re deteriorating, then we’ve got the carpet problem again. And something’s moving that we don’t understand in that datum. So updating with all the new space geodetic data that we’ve been collecting over the last 20 years is really what is allowing us to modernize this datum.
So we’re going to replace all three NAD 83 frames and all vertical datums with four new terrestrial reference frames and a geopotential datum. The new reference frames are going to rely primarily on GPS or the Global Navigation Satellite System it’s within. So if you’ve been part of GPS for a while, we started out where all we had was a suite I think when I first started surveying for NASA we had 20 maybe satellites I think that we could see. They were just GPS. Now we have we have GPS satellites from all over the world and that is a larger array called the Global Navigation Satellite System. That just gives us more satellites in the sky, more sky coverage, and a better chance to to capture at our receivers when we’re surveying much more accurate points. So we will be um using primarily that data as well as the GRAV-D gravimetric um data that I was talking about that’s being flown across the country right now. These new reference frames will be easier to access and maintain than the current one, which relies on these old physical survey marks that deteriorate over time. So we’re going to call that new reference system the Modernized NSRS. The release of the Modernized NSRS was initially projected to be this year and so it will be named the NSRS 2022 or the SPCS 2022 for State Plane, but the actual projected release date for both is is now looking to be sometime in 2025.
Matt Peters: I, you know, there was just to take a little side note, can you tell me quick what the GRAV-D survey is?
Lynda Bell: Yes, I know I was throwing a lot of acronyms out quickly. So spelled out that is the Gravity for the Redefinition of the American Vertical Datum Project. GRAV-D. And so we’re flying gravity surveys from airplanes across the country. And we’re ground truthing them too with surveys that are done primarily at airports across the US. So we’ve we’ve had several being flown right here in our region of Utah, New Mexico and Arizona just since I’ve been on-boarded. I think there’s been two big airborne GRAV-D surveys flown. So we’re really, that is really what we’re using to redefine the vertical.
Matt Peters: Is it some kind of a LIDAR or what?
Lynda Bell: It’s a gravimeter. Basically, and I think it’s both LIDAR and gravimeter being flown on a plane and measuring as it flies. And then there’s ground-based gravimeters as well. So there’s, I think like I said, most of the ground-based survey points are at airports. And they’re then just ground truthing the flown data. And you know, I’m not sure everything that’s flown from that plane, it could be that we have a combination of data coming in from anything orthometric and all kinds of cool stuff. LIDAR as well.
Matt Peters: So all this, all these things you’re speaking of, what type of educational and experience background did you have?
Lynda Bell: Well, I’ve been at this for a little while and I ended up in geodesy because I started out with a degree in geophysics from Virginia Tech. And the story, can I tell a story, is that okay?
Matt Peters: Sure, sure, sure.
Lynda Bell: Okay. So the very untechnical, unglamorous way that I got my first job, which was at NASA, was I was a sophomore undergraduate in geophysics at Virginia Tech and I had my Virginia Tech sweatshirt on. And I rented a canoe, I was a lifeguard at a campground at a state park in Maryland. And I didn’t know that the person in the family that I was renting a canoe to was a NASA engineer. And he was from UVA and I was, you know, just a young Virginia Tech undergrad. And he teased me about what school I went to because UVA and Tech were rivals and still are. And he said, “What are you studying?” And I told him Geophysics. He said, “That is really interesting. What kind of classes do you take?” I said, “Oh, lots of physics and lots of mathematics and advanced math and I have a minor in geology and a major in geophysics and I’m doing Fourier analysis.” And he said, “All of that as an undergrad?” I said, “Yeah, it’s really hard.” And he said, “You know what, we have an internship program we’re starting up at NASA Goddard for students with backgrounds like yours if you’re interested in it. Here’s my colleague’s name and number.” So I, you know, I just very nervously went home and told my folks about it and they were like, “Oh my gosh, are you kidding? Get in touch with them right away.” So I did and I interviewed and got an internship at NASA Goddard after my sophomore year at undergrad.
And I worked for the Crustal Dynamics Project and the Geodynamics Branch of NASA Goddard. And I worked mostly with radio astronomers who were using VLBI or Very Long Baseline Interferometry, which are those big dishes like you see in the movie Contact with Jodie Foster at the VLBA. And we were just starting to, they had really started to obtain some of the first real measurements of crustal motion when I was an intern. And most of them though were looking at the sky and I and my bosses who were people from like MIT and just these amazing, brilliant, brilliant people said, “We’re going to try to understand what these measurements you’re taking from quasars in deep space are showing us on the earth.” And lo and behold we were seeing as we analyzed the data vectors moving in the directions of plate motion. So I was very, very lucky that just as an intern wide-eyed studying under the masters I got a chance to be part of that early work of geodetic surveying.
And I went out later and started working with GPS and we did footprint networks around the VLBI network. We started working in Alaska studying plate motion there, seismic prediction across the San Andreas Fault in California. So that was really neat to get to be part of that work coming back around later in graduate school, working again supported by NASA but through grants in academia at that time. And so that was my educational path. And then I’ve gotten a chance to work also for the National Park Service when I was in grad school as the Sea Level Specialist improving water level monitoring in US ocean and coastal national parks. I worked a little bit in between all of that grad school and work as an adjunct prof and a curriculum developer for a couple of schools, University of Maryland, a couple of schools back East. And that that gave me some chops on teaching and and how to develop training materials and things, part of which is part of my job now. And now I’m serving as your Southwest Regional Advisor and I’m a full-time civil servant for the US Department of Commerce.
Matt Peters: Wow. You’re making me tired.
Lynda Bell: It was a long path but it was interesting. It really I have to say that the path for me was just driven by curiosity. I was working with brilliant scientists from the very beginning and they taught me to be curious and think outside the box and and always look for the next question to ask. And when I then became a science teacher in college classrooms, that really is what I taught my students, that science really is inquiry. And if we’re doing good science, one question should just answer or lead to another question, not an answer. So I really think I have my early mentors to thank for that that dream. Yeah.
Matt Peters: Yeah. There was one thing I I kind of wondered about with that, you know when when you talked about how you met the gentleman, you know with the canoe. I I can’t tell you how many stories or how often that same kind of thing has played out where you sit down somewhere, have a drink with someone, your paths cross, the future blooms. Yeah, it’s pretty crazy.
Greg Bunce: And I think it’s just staying curious. I think that that’s the key there for me as well. And I and I like to I like that point that you made.
I’m also curious about so you mentioned terrestrial a couple times early on. A lot of the the some of the original datums were all you know based on terrestrial stuff. So I’m thinking of benchmarks and I’m thinking of monuments. And we’ve heard of something called the GPS on Benchmarks and and how some of us get involved in that. Are those referring back to the terrestrial benchmarks and kind of GPSing those? Can you talk a bit about that program?
Lynda Bell: Yeah, most definitely Greg. And that is exactly what it is. By definition, we call it our GPS on Benchmarks or GPS on BM program and it’s just a crowdsourced data collection program that helps your community prepare for the modernization of the NSRS. It’s a little bit like geocaching really for folks that like to go out for fun. A lot of times we have retired surveyors help us, community groups, scout groups will go out, young students who are just training on surveying. It doesn’t you don’t have to be currently employed as a professional to help us with this. But the idea of it is to help us increase our knowledge of geodetic positioning on these these benchmarks in your area.
So for the last 200 years actually, the nation’s foundational mapping infrastructure has relied on hundreds of thousands of survey marks set in the ground across the country. So in 2007 NGS embarked on a decades-long endeavor to update the mapping infrastructure to take full advantage of modern technology and dramatically improve the accuracy of height measurements. To fully realize the billions of dollars in benefits that would come through moving to the modernized NSRS, federal and state and local governments and private sector firms are all going to need to prepare and adapt their procedures and workflows. So our program, GPS on Benchmarks, harnesses the power of partnerships across the country to move us all along the path toward realizing the benefits of the modernized NSRS.
And Greg you had asked too like what can we do locally? When should states be involved? I just wanted to say that your state can be involved right now by organizing and and Utah is by organizing mark recoveries and updates of passive control status, tying your local control stations to the NSRS. And you can just go out and observe like if you can get two hours that’s great, four hours is going to be even better data for us, GPS sessions on your marks. You can run RTN check stations to get updated coordinates on your marks in your areas. And then finally by blue booking and publishing your data with NGS your state then can be better prepared because your your local control is going to be more accurate.
So to do this if you want to do this, if you haven’t been involved in a in a GPS on Benchmarks campaign in the past, we have a prioritized list of survey marks in each state across the country where new data would really help us. So I that information will be in the notes and please feel free to contact me or go and find out more about that. We have a link where you can click directly on that list of marks in your state and go out and find them. So first you search for it. You get your your NGS datasheet and your to reach description and you get in your truck and you go out and find it. Maybe you’ve seen it before and you know of it of that site. You find it, you report back about the condition of the mark by taking we we have a little listing on our website of of directional photos to take of the mark. And then if you have access to survey grade GPS equipment then you can just collect some data on those marks. Two to four hours and then share it with NGS. So there’s two steps to it. If you don’t have any GPS equipment just recovering marks and reporting back about the condition also helps. So there’s there’s a lot you can do, especially even citizen scientists if they want to get involved. Mark recovery is a super fun field activity for folks to do.
And we did have a cutoff date to submit GPS on benchmark data for use in the 2022 transformation tool. We moved it to the end of this calendar year. It was a year ago. But I’m Galen Scott who’s our constituent manager said they may even extend it further because we we want to give people a chance if they just heard about this to jump in and help us. So more detailed information and links can be found at the website that we’ll put here on the podcast which is just geodesy.noaa.gov/GPSonBenchmarks. So we hope you’ll be interested in joining us.
Matt Peters: Yeah I’m sure we’ll we’ll get some takers on that. I am curious though, so you’re doing the GPS on Benchmarks and I’m assuming that this is in support of a vertical datum. And I’m wondering how does the terrestrial benchmarks and the GNSS system kind of work together to to produce a new vertical datum?
Lynda Bell: That’s a really good question and that really comes down to our Online Positioning User Service or OPUS software. And so what happens is and we provide training on the OPUS software as well so that we can help you not only learn how to use it but to be a manager for your company or for your local constituents that you work with. And it’s basically if you think about putting all that data that you just talked about Matt like into the hopper, like into a hopper. And that hopper is all the all the transformation equations that our geodesists at headquarters are writing in our software code. And that comes in and then you create something called a session. And that session has all the marks that you surveyed in it, all your GNSS data. And then you have what are called CORS stations that are in your area. And I know you guys are familiar with those but for some of the listeners if you don’t know what a CORS is, it’s a Continuously Operating Reference System or station. We have a grouping of them all over the United States. There’s a good handful of them in every state. They are generally built and managed by local constituents, often our departments of transportation. And once the data is broadcast to NGS then we ingest it and we provide accurate positions with those continuously operating reference stations. So you’ve got 24/7, 365 days a week at those stations all across your state, all across the country. And we use those to pin down your session of data that you input. So once you lock those down which we are pretty comfortable and accurately knowing the behavior of those stations, then we solve the solution with all of your incoming data that was in the hopper with those CORS stations as the underpinning for the reference system and we give you accurate positions on the other side. So it’s kind of like magic in a way. A lot of people do it with commercial software these days, all the time just click and point and get your positions. But we’re trying to really work on educating the community to help everyone understand what’s behind the scenes, who is Oz behind the screen on all of this so that we can all be part of the pieces and parts we all can be part of in preparing for this more accurate reference system.
Matt Peters: Yeah. Are there are there other programs that states should be involved in?
Lynda Bell: Absolutely, yes. We have many. We really depend on the strength of our users to build the modernized NSRS. So the GPS on Benchmarks that we just talked about is one program states can be involved with. You can publish your data with NGS through OPUS. Again on our website we’ve got training webinars all kinds of cool things where you can learn more about that if you’ve never used OPUS. And you can also submit to the State Plane Coordinate System calls for proposals. So we talked about that earlier in the broadcast as well.
We have a really really active and and well well put together education outreach program at NGS. So if you want further training on our products and services, if you want to find out more about how you can get involved to help strengthen the modernized NSRS then you can contact your NGS Geodetic Coordinator at your state level or your Regional Coordinator Advisor which is me. So in Utah your State Geodetic Coordinator is right there at UGRC, Sean Fernandez. And he works at the just to give UGRC a a shout out, it’s the Utah Geospatial Resource Center and it’s the state of Utah’s map technology coordination office and they’re the fine folks hosting us today. And then I’m your federal regional advisor and I also serve the states of Arizona and New Mexico. So between Sean and myself if you’re in Utah reach out to us. Go on the website that we’re going to provide as well in the notes and we’ve got trainers and teachers and folks to help you with anything you might be interested in.
Greg Bunce: So NGS is tucked under NOAA. Can you explain why that’s the case or why that’s a good fit, Lynda?
Lynda Bell: Yeah, that’s a good question Greg. And you know I proudly have my NOAA patch on my hat and and my sticker on my GOV and all of that. And people say, you know, what and here I am in the Southwest. So people say, “Well what and here I am in the Southwest. So people say, well what’s NOAA doing out here?” And I got that same thing when I worked for NASA and told them that I was an earth scientist they would say, “Why is an earth scientist at NASA?” So the the short answer is that a lot of these big agencies in our country are really kind of the umbrella over all of us that are doing specific things inside of it. So NGS is actually within NOAA’s line office which is called the National Ocean Service. And there’s actually seven programs and two staff offices inside of that. Everything from CO-OPS, the National Center for Coastal Ocean Science, us, the National Geodetic Survey, Office for Coastal Management, Office of Coast Survey, IOOS. And so all of that sounds pretty ocean heavy but we talked a minute ago in the broadcast about this idea of positioning and why NGS focuses on that. So NGS and the National Ocean Service are then under the broad far-reaching service of NOAA. Which again out and about in public people don’t always know what that means. They’ll think NOAA is that a guy’s name? What does that stand for? They or is it Noah like Noah’s Ark? So actually what N-O-A-A stands for is the National Oceanic and Atmospheric Administration. And we’re within the US Department of Commerce.
So inside of NOAA we have um this I think a lot of people know about NOAA satellites because we think about our weather right? So NOAA’s satellite service is called the National Environmental Satellite Data and Information Service or NESDIS. And it’s what’s providing that secure and timely access to all the global environmental data and information from satellites and other sources that we take for granted and use every day to promote and protect the nation’s security, environment, economy, and quality of life. NOAA’s mission is to understand and predict changes in climate, weather, oceans, coasts, and share that knowledge and information with others. To conserve and to manage coastal and marine ecosystems and resources as the nation’s authoritative environmental intelligence agency. So how does NGS fit inside of that? Well we might need to think a minute about the earth. And we often think of the earth as just this round smooth globe like we see in pictures. But in reality its shape and surface are very complex. And this complexity provides challenges when trying to determine the latitude, longitude or elevation of a point on the earth’s surface. And that point could be the surface of the ocean, of an ice mass, the bottom of the ocean, a land mass. It could be all kinds of different landscape everything from a marsh to hard rock at the top of a mountaintop to shifting sands on a beach. If we’re trying to determine those points accurately we have to figure all of this out. And how we do that is we put this inside of something called geodesy. And that is the science of geodesy and it’s really its own branch of science now. When I was in school as a young geophysicist we had classes on geodesy but it wasn’t a major yet. Now it’s a major all the way up to a PhD. And what geodesy is is the science of accurately measuring and understanding three fundamental properties of the earth: its geometric shape, its orientation in space, and its gravity field. As well as all the changes of those properties with time. So at NOAA under the National Ocean Service, geodesy is the business of the National Geodetic Survey. So again we’re sort of an underpinning under all of that great environmental science work that’s being done in NOAA.
Matt Peters: So you know now that you kind of mentioned that it kind of uh kind of pushes me around a bit and I remember, hey hey we’re only just one country on the earth. And so when I think about all the things you’re talking about and the underpinnings of the planet, what what’s the coordination with other uh countries?
Lynda Bell: That’s a really good question Matt and I’m really proud to report on what we do um outside of the US. So of course thinking about all this work we’ve talked about today we’re very very busy just right here in our own country and then certainly at the state and local level all of you are very busy as well. But NGS because we’re under the hat of NOAA and the Department of Commerce, collaboration with other countries is very very important. So we are very active and NGS geodesists travel the world and we collaborate with fellow scientists and policy makers. NGS actually works with the United Nations. We work um we have several of our top geodesists who sit on the United Nations Geospatial Sessions, the International Global Navigation Satellite System Service, the United Nations Pacific Geospatial Conference, the Canadian Geodetic Conference, and Cuba’s National Office of Hydrography and Geodesy. So those are some of our like everyday roles that we we hold those positions in those conferences and in those committees so that we have a voice on the international stage when these discussions come up. And you can imagine at the international level again because this is this is about security and positioning, that can underpin everything from national international security during wartime, it can underpin um discussions on climate change. So you can imagine some of those discussions at the UN um the detail and depth that they go into. And it’s very very important to have international um geodetic reference frames that we all can talk about on the same page. And NGS is a really big part of advising on on the international um reference frames.
So just um just a quick shout out just to show you how active we are. Just in the last 30 days um our Chief Geodesist um and a US representative of one of our advisors just attended the 12th session of the United Nations Committee of Experts on Global Geospatial Information Management. These kinds of participations strengthen relationships with other nations as well as addressing mutual interest. The participants at this meeting agreed that there’s a need right now for enhanced technical relationships between the marine and terrestrial domains to better measure and understand physical height interactions between land and water especially during these dramatic changes that were seeing with sea level change and climate change. Um so this also bolsters our relationships with federal partners too and within NOAA. And particularly we’re um missioned from the Office of Coast Survey to to interact internationally.
Um I just talked a little bit about um the the really cool survey going on right now in the Great Lakes. We’re working with Canada, that’s an international relationship there with our Canadian partners to update the International Great Lakes Datum. And then more specifically to sort of what we were talking about earlier of modernizing the NSRS, this I think is really important because I’ve heard people ask me this a lot at conferences or in phone calls is are these new changes going to be in our equipment that we use out in the field every day? So NGS just hosted representatives from leading global survey equipment manufacturers and geospatial software from all over the world to discuss those recent changes and future developments for NGS’s OPUS. So we’re right now working with sharing our algorithms um with the commercial sector so that surveyors and engineers when they’re out in the field will have this these new algorithms embedded in their instruments and in their software. So this is a really important meeting and it was part of an ongoing strategy to really engage the geospatial community on OPUS and ensure developers build those tools to help the constituents reap the benefits of that modernized system.
So right now one of the very specific things that I’m going to be talking about this in some of the conferences I’ll be touring in this next year, we actually have set up a more comprehensive standard file format. So surveyors can then input into that hopper Matt we talked about earlier um GNSS measurements as well as leveling, angle, distance, azimuth and relative gravity measurements. So these are the kinds of things that we’re doing at the international level and I think it it really enhances um and improves our work at the national and local level as well.