Why Terrestrial Reference Frame and not Datum?
NATREF2022 stands for “North American Terrestrial Reference Frame of 2022”. It is going to be the new national reference, replacing NAD83. So why “Terrestrial Reference Frame”, and not “Datum”? On the NGS web site, the page that has all the information about the new systems is titled “New Datums”, so one might infer that they mean pretty much the same thing; they do. The difference is at an academic level. Geodesy is an interesting field because there are subtle nuances to word definitions, and slight differences to how those words are used in other mathematical sciences such as geometry. “Datum” in a mathematical sense, is simply a singular form of “data”. In geodesy, this indicates a single point from which to begin measurement in a relative measure. Classically, our geodetic datums are formed from the location of a single place of reference such as an astronomical observatory. In modern systems, they are formed by a network of points that are geometrically related into a single collective, a sum of many parts, rather than relying on the single point as an anchor definition. So rather than defining it by a single point out of many, it is recognized as a geometric network, and the reference that network provides is a Geometric Reference Frame.
I’m going to say it: Conceptually, a geometric reference frame is just a new datum.
To the GIS practitioner, map maker, or surveyor, they provide the starting point and context for our relative descriptions of location. Geometric Reference Frame is currently the popular term in geodesy. It is academically appropriate and conveniently serves as a way to make the new name different from the old, which in this case I can get behind. Can you imagine reading someone’s sloppy handwritten field notes of NAD27 vs NAD22? It would invite disaster. Sometimes, change for the sake of change is not a bad thing. So aside from a mouthful, what are we getting?
From “Fixed” to Time-Based Reference Frames
There are actually going to be four new reference frames: One each for the Continental US/Canada/Mexico; the Mariana [tectonic] plate; the Pacific plate; and the Caribbean, each with similarly abbreviated names. We’ve never had that kind of unified coverage before, so that’s pretty cool. Each of these frames will be plate-fixed, but also, at the time of realization, geocentric. This gets right to the heart of why this is happening now. As it turns out, NAD83 wasn’t as geocentric as intended when it was created. That is to say, the middle of the datum should theoretically have been at the geocenter but it wasn’t; it was off by about two meters.
Over time, with tectonic motion, the effect of this offset grew and its effect on surface positions could no longer be ignored. What does that mean? Well, most of our positioning work in modern times is done based on GNSS devices (Global Navigation Satellite System), GNSS by nature is geocentric since the positions are calculated from satellites which orbit the center of mass of the planet. If our national reference frame is not geocentrically related, then it is not directly compatible with GNSS. As motion continues into the future, the new models will acknowledge this and will dynamically change over time following the rotations and motions of the plates. This is necessary because if we are working on the surface of a plate that is moving relative to the geocenter, we need to track that motion if our survey devices stay with the geocenter. So once again, the new models are fundamentally different from the old and a significantly different name will really help to acknowledge that. This is going to require a new mindset for a lot of GIS users. Right now, many still deal with coordinates in “fixed” reference frames where we may acknowledge a reference epoch (date), but that date isn’t actually used for anything other than metadata. Time-based coordinates are inevitable in the future, so it’s time to start getting comfortable with them.
One question I heard directed to the NGS at the Summit was along the lines of, “If we’re just going to have to update again in a few years, why don’t you fix the problem at 2022 so we don’t have to deal with it again?” The problem here is not with the system that needs to be updated (with the implication being that it is flawed now), but in our understanding of the system we’re moving to. We are currently using a system in which we don’t acknowledge that things move and a lot of people have come up through their careers comfortable with there being a fixed relationship between any two given coordinate systems. We are moving to a system where time is not only a factor, but is fully acknowledged as necessary in a moving system. Data epoch is no longer optional. We need to know where our data was and when it was there in order to know where it is a few years later.
Under the hood of this new name NATRF2022, we are adding an entire dimension of measurement, and that’s far more exciting than adding a few new words in the name of the datum.
Preparing for the New Reference Frames of 2022
Over the next few years, we will need to make a few fundamental changes to GIS in order to be ready. First and foremost, we need to make sure our colleagues are comfortable with the new terminology and the concepts of time itself as being an important part of position. After the new systems are in place, we will likely also have new projected coordinate reference systems to deal with. It is very likely that we will have new versions of the US State Plane coordinate system zones. Furthermore, many states are undergoing a push to support new Low Distortion Projections such as the efforts in Minnesota, Wisconsin, Oregon, Iowa, and others. With 4 new plate models, we’re also going to have new Coordinate Transformations to relate them to each other and the older systems, the new reference frames will require it.
As a key player in the geospatial software industry, Blue Marble is already working on changes to our software in preparation for the upcoming new reference frames. Much of this will be invisible in our tools for the time being, while other components are already there, such as epoch settings, transformations that are not stuck to WGS84, and the ability to dynamically bring in new parameters to the database. We have been paying attention and are ready for the coming changes and will strive to help our users be ready, too, as we all learn exactly what these new reference frames will look like over the next five years. As an industry, we have grown very comfortable and perhaps complacent with our systems and transformations in the US for some time. Change is coming, and the time to prepare is now.
Sam Knight is the Director of Product Management for Blue Marble Geographics. With Blue Marble for over 13 years, Sam has lead hundreds of GIS and Geodetics courses and is a frequent speaker at industry conferences, trying to make tricky geodetics concepts accessible at a practical level.
The Monthly Blue Marble Geo-Challenge
Name the capital city? – Port of Spain
Name the river? – Colorado River
Name the country? – Togo
Name the island? – Corsica (Corse)
Name the lake? – Lake Geneva (Lac Léman)
DroneMapper is one of the success stories in the fledgling field of UAV data collection and processing. After several decades of experience working in the aerospace industry, CEO Pierre Stoermer was quick to recognize the potential for drones as a viable low-cost alternative to manned aircraft for this purpose. Serving customers in a wide variety of industries and business sectors, including agriculture and mining, Stoermer recognized the importance of efficient data management and processing, both for their internal processes and for the value added products that the company delivers to their customers. This lead Stoermer to Global Mapper for UAV data processing.
Like most small businesses, one of the main challenges faced by DroneMapper was finding tools that provide the right level of functionality but that fit within the company’s inevitable budgetary constraints. As with any business expenditure, investing in technology must bring some degree of assurance that there will be a return on this investment. Traditional GIS applications are notoriously complex and cumbersome, requiring an inordinate amount of time and a high degree of training and expertise to effectively operate, which significantly impacts the overall cost of any project.
Without a dedicated GIS technician at DroneMapper, the operation and maintenance of the GIS data processing workflow is the responsibility of the current staff. The selected software must therefore be easy to learn and easy to apply.
DroneMapper has an expanding client and customer base, whose needs and requirements necessitate an efficient data processing platform that can generate deliverables in a wide variety of formats and with varying specifications.
Unlike most companies who, when faced with a technology decision, evaluate multiple software alternatives, DroneMapper found Global Mapper first and has stuck with it. The range of functionality in tandem with the unparalleled format support were enough to convince them that Global Mapper was an ideal solution for their needs.
This versatile, fully functional GIS application has been steadily gaining an eager and dedicated worldwide following among geospatial professionals. Recent development work has focused on the visualization and analysis of 3D data, especially LiDAR and other point cloud formats. According to Stoermer, “Global Mapper provides an outstanding set of tools for efficiently assisting us and our client base in an affordable manner”.
GLOBAL MAPPER FOR DATA PROCESSING
Global Mapper is at the core of most of DroneMapper’s data processing workflows. The company employs the software’s intuitive 2D and 3D visualization tools to provide initial quality control of ortho-rectified imagery and DEMs.
Further along the production line, Global Mapper is the go-to application for filtering point cloud data to create accurate, bare-earth Digital Terrain Models. These DTMs allow the company to generate customized contour lines that can be exported in shapefile or virtually any other vector format. Global Mapper’s powerful cut and fill analysis capability and volumetric calculation tools are used to precisely measure volumes, providing DroneMapper’s clients in a variety of industries with site-specific intelligence that is essential for efficient project management.
Employing Global Mapper’s powerful raster calculation functionality, DroneMapper is able to quickly and accurately analyze vegetation patterns by generating NDVI grids. This provides an invaluable service to clients in the agriculture and forestry industries.
DroneMapper’s decision to settle on Global Mapper for its spatial data management allows the company to perform both internal data processing as well as customer services on one powerful and easy-to-use platform. The application’s SDK will also provide an opportunity for future custom development projects and will allow DroneMapper to adapt Global Mapper to more specifically meet their needs.
ABOUT GLOBAL MAPPER
Global Mapper is an affordable and easy-to-use GIS application that offers access to an unparalleled variety of spatial datasets and provides just the right level of functionality to satisfy both experienced GIS professionals and beginning users. Equally well suited as a standalone spatial data management tool and as an integral component of an enterprise-wide GIS, Global Mapper is a must-have for anyone who deals with maps or spatial data. The supplementary LiDAR Module provides a powerful set of tools for managing point cloud datasets, including automatic point classification and feature extraction.
ABOUT BLUE MARBLE GEOGRAPHICS
Trusted by thousands of GIS professionals around the world, Blue Marble Geographics is a leading developer of software products and services for geospatial data conversion and GIS. Pioneering work in geomatics and spatial data conversion quickly established this Maine-based company as a key player in the GIS software field. Today’s professionals turn to Blue Marble for Global Mapper, a low-cost, easy-to-use yet powerful GIS software tool. Blue Marble is known for coordinate conversion and file format expertise and is the developer of The Geographic Calculator, GeoCalc SDK, Global Mapper, LiDAR Module for Global Mapper, and the Global Mapper SDK.
Congratulations, you have decided to evaluate Global Mapper! You know that Global Mapper will be a great addition to your workflow. But now you face a decision; what kind of license do you need? We can help you find a license solution that will work best for you! Who are we? We are Carrie and Rachael, sales support specialists and unofficial license gurus. So, we know when it comes to selecting a license solution there are a few questions that you need to ask yourself: How many computers do I want to license? Do you need to access the software remotely? Do you want to share the software with co-workers?
How many computers will the software be on?
A seemingly simple question can save you time and money. If you are purchasing the software for yourself, and the license will reside on one computer, then a single user license, sometimes called a node locked license may be the best option for you!
The Single User Machine Locked license is registered to one computer. The license itself is written to your computer’s Ethernet port (using the MAC ID and the MAC ID must be static). However, if you have a Windows 2 in 1 laptop or tablet you may have difficulty licensing your computer. This is because some of these devices might not have a stable Ethernet port. Should you encounter this problem, please contact our licensing team at firstname.lastname@example.org.
If you have a single machine license and need to move it to another computer, there is a license removal tool you must use in order to generate the proper removal code needed to complete this process. This process can be automated; both the old and new machines must be connected to the internet during the removal or activation process. This allows your computer and the application to properly and quickly communicate with our licensing server. If you re-image your machine, perform an operating system upgrade, and/or change hardware, please properly remove the license BEFORE any updates are made. Please note that remote desktop (RDP/RDS) is incompatible with a single user license. If you are looking to utilize RDP/RDS, our network server licenses are compatible with this functionality. The single machine license can be moved twice per year.
If you need to frequently move the license or share it with others, keep reading for more licensing solutions.
How many people will need access to the software?
Do you have multiple people who need to access the software? Are they all in one office? Are they at different locations? Do they work from home on a remote desktop? Do you have a limited budget and want to get the most software for your buck? If you answered yes to one or more of these questions, then a network license may be the answer for you! Network licenses are sold at a minimum of two seats. We haven’t run into a maximum seat limit yet so if you need 100 seats, not a problem!
Network Licenses are a convenient and flexible way to manage a pool of licenses. Network licenses are designed to provide broad access to the software where an individual license may actually serve only one person. The network license can serve one or as many as you like depending on how frequently they use Global Mapper. The network license can be shared not only internally but also across office locations and the seat count is the number of concurrent licenses (users) that can be utilized at one time. Heading out of the office? Not a problem, the network license comes with a convenient borrow feature that allows for a license to be “checked out” and used off the network for a set period of up to 90 days. When that expires the license is automatically returned to the server. This feature is perfect for business trips, going out in the field, working from a ship, temporary employees or a vacation. Yes, you can even take Global Mapper on your vacation. Network administrators love this option as there is only one file to maintain and update. No need to track individuals or physical hardware.
If you are thinking to yourself, “these options are not what I am looking for,” that is okay! Blue Marble has four different licensing types, so we have two more options for you to choose from. In our next post we will be covering the USB Dongle and the Single Floating licenses (portable or virtual license with extreme flexibility).
If you want to learn more about how our license options can provide the best return on your investment please contact use directly, we love to talk about licensing! Send an email to email@example.com .
Carrie Strauch and Rachael Landry are the unofficial license guru’s and the official Sales Support team. Together they bring over 30 years of customer service expertise to Blue Marble. They are the people you are most likely to work with when you call or email our office, and they are always ready to answer questions.
Welcome back! In my last entry, Back in the Day Part I: Making Paper Maps from Scratch, I barely scratched the surface about how printed maps come together. I talked about scribing roads by hand and creating a duplicate negative image from that artwork. Why a negative image? Well let’s take a step back from the actual content of the map and talk a bit about how the printing process actually works.
Most materials you see printed on paper come from a negative image — newspapers, magazines, baseball tickets, paper money, all of it. Printed on paper from some master source that happens to be upside-down and backwards, usually a plate that has been “burned” in a vacuum frame. Some images are black and white, some two-color (black and white and one color) and some four-color, also known as “four color process” using CMYK — a conventional color model for printing, similar to RGB in the digital universe.
So what is CMYK? Sounds like a European hockey team doesn’t it? CMYK stands for Cyan (Cyan or blue, it actually resembles more of a turquoise than anything), Magenta (“process red” that looks more like hot pink), Yellow (enough said), and Key (really, it’s black, but the old timers refer to it as “Key” because the other color plates were registered, or “keyed,” to the black plate during the printing process). When blended together, these four colors create a wide range of tones and hues that you and I interpret as a full spectrum color image.
When printing a map in CMYK, four sets of negatives are required, organized by color. We call these negatives “flats.” For example, a set of Cyan flats would contain features that appear blue on a map, such as open water and hydrology. Cyan flats will also contain tones that contribute to compound colors, such as greens and purples. The same principle applies to magenta, yellow and black flats. We can think of these flats as being similar to layers in digital mapmaking. Each layer adds details to the map, in this case, the flats are adding color. Often times we will have five or six flats for one compound color.
In order to achieve the correct color tone, screens need to be applied to certain map features that we don’t want to print at 100% strength. When we print open water, for example, we use a 10% screen so that when the map gets printed from our open water negative, only 10% of the cyan will print on the paper, resulting in a light blue tone. These screens are measured by percentage and would be merged with other objects in composite form.
When all of the flats of each color have been composited (burned) on their respective plates (there should be four, right? Cyan, Magenta, Yellow and Black — see? You’re catching on) The printers take these plates and register them on the press and start printing the “signatures.” A signature, or sig, is basically a printed sheet (both sides) that contains multiple pages. These sheets are then folded in a certain way so that the pages appear in sequence, like a book. When I was a map technician, each atlas had a good number of signatures that were printed in order (1 through 12 for example), but keep in mind, the total signatures in the job reflected how big the atlas was. Alaska and Texas had over 30 signatures while Maine had only 12 sigs, for example.
After the signatures are printed by all four plates (CMYK), they are then sent along to the bindery where the sigs are trimmed to become one uniform size, then collated and bound into books that you and I recognize.
It’s fair to say that my bosses at the publishing company didn’t trust printers. Whenever we sent atlases for printing, we would order 30,000 or 50,000 books at a time, which, as you can imagine, was an expensive investment. We as publishers, also had to purchase our own paper. so there was no going back if a job got botched. Too many times books would come back with inconsistent blues, reds, greens, you name it.
In order to combat this problem, the map technicians would go on “press checks”, meaning we would QA/QC each signature after the plates were hung and the printing started. If the book had 36 signatures, that meant we did 36 checks. If we were printing 30,000 books, it would take 3-4 hours to print a signature. Every three hours we would be taken into the pressman’s area, shown a printed signature, and sign-off on it before they were given the OK to continue printing. This is what we did every three hours, non-stop, until the job was done. Overnight checks were brutal, and yes sometimes this would go on for days. Plenty of Mountain Dew and Diet Coke, let me tell you.
The golden rule for QA/QC was “CRC”. COLOR, REGISTRATION, CONTENT.
So after our map is printed, the books hit the shelves and they start selling like hotcakes. All according to plan, life is good. Then the phone rings in the Revisions Dept., and there’s someone who’s not too happy that their private driveway ended up on page 34.
Kris Berglund is currently the Vice-President of Sales at Blue Marble Geographics and has been with the company for over fifteen years. Kris has been involved with digital mapping technology for over twenty years, and demonstrates a diverse level of experience in cartography, geomatics, technical sales & marketing and business development.
As an inherently versatile and interoperable GIS application, Global Mapper has become an essential component of the geospatial toolkit for companies, government departments, and organizations of every imaginable size and type. While the software’s popularity in certain market segments can be directly attributed to a preemptive marketing strategy by Blue Marble, the same cannot be said of the Unmanned Aerial Vehicle (UAV) industry. Instead, the reason why many UAV operators found and embraced Global Mapper can be attributed to word-of-mouth recommendation from others in the field.
With the rapidly expanding use of UAVs for commercial data collection, a bourgeoning market has emerged for data processing software tailored to the needs of the needs of the UAV community. Consequently, many commercial and open-source software developers have jumped on the bandwagon and have begun the process of creating tools to address this demand. Global Mapper, on the other hand, has been around for almost two decades and has proven to be ideally suited to the requirements of the UAV industry. For many UAV operators, the quest to find an affordable, easy-to-use, yet powerful data processing application has ultimately led them to this remarkable application.
So what role does Global Mapper play in commercial UAV operations?
Global Mapper’s expansive streaming data service provides access to a wealth of invaluable map layers that form the foundation for the mission planning process. High-resolution aerial imagery and terrain layers can be accessed on-demand providing an initial three-dimensional visual context for a project area. Locally available vector files can also be overlaid to address concerns such as property ownership, regulatory issues, potential obstructions, and optimal takeoff and landing sites. Intuitive digitizing and drawing tools can be employed to delineate and measure the extent of the project area and supplementary attributes added to record the flight details in their spatial context. Finally, a high-quality project proposal map can be generated in georeferenced PDF or hardcopy format for sharing with a client or customer.
For most UAV operators, the true value of Global Mapper comes to the fore after the mission has been flown. Transforming raw data into a viable commodity or finished product is Global Mapper’s forte, and image processing is a major part of that workflow. The software offers a powerful image rectification tool for applying geographic intelligence to captured images by anchoring them to known coordinates or manually placed control points. Multiple images can be mosaicked or stitched together to form one contiguous file and the overlapping images can be feathered to smooth the transition from one image to the next. Image manipulation options are also available including contrast, saturation, and transparency adjustment. For advanced users, a raster calculation function can be used to analyze the characteristics of multiband images using a predefined or custom formula, the most common of which is NDVI analysis for vegetation assessment using the red and near infrared bands.
Point Cloud Processing
Increasingly, UAV operators are generating 3D point cloud files during the data collection process. Traditionally this data, often generically referred to as LiDAR, has been collected using piloted aircraft at relatively high altitude resulting in lower density point coverage. As the raw material for terrain analysis or feature extraction, the quality of the final product is intrinsically linked to this point density, so UAV-derived point cloud files are typically superior to those derived from conventional LiDAR collection. Global Mapper, along with the optional LiDAR Module, offers an array of LiDAR processing tools for editing, cropping, and filtering the data. Noise points can be systematically flagged and removed and a vertical quality control process can be implemented to adjust the elevation values to surveyed control points.
For most LiDAR or point cloud users, terrain analysis is the ultimate objective, a process that requires the non-ground points to be initially identified and filtered from the data. Using the remaining ground points, a simple gridding process transforms the XYZ values into a raster Digital Elevation Model: a three-dimensional representation of bare earth. Many of Global Mapper’s advanced analysis functions are derived from this gridded data, including watershed delineation, line of sight analysis, and view shed modeling. For UAV-collected data, one of the most powerful and commonly used terrain-based functions is volume calculation. Global Mapper offers a variety of tools for this purpose from simple pile volume calculation, derived from delineating the bounds of the pile or depression, to the more complex cut-and-fill optimization process, in which the terrain is flattened to an elevation that equalizes the volume of material to be cut and filled.
The advent of UAV-collected, high-resolution point cloud data has led to a myriad of applications for the technology: from vegetation monitoring to archeology. To address the growing need to detect recognizable patterns within the data, several automatic reclassification tools have recently been integrated into the Global Mapper LiDAR Module. Points representing buildings, vegetation, and utility cables can be identified and reassigned to the appropriate LiDAR class. These reclassified points can then be used to extract or create 3D vector features (points, lines, or polygons) of the objects they represent. A manual extraction option is also available whereby custom lines or areas can be created using a series of cross-sectional views through a point cloud. Feature extraction can also be applied to imagery allowing patterns of pixel colors to be used as the basis for creating polygons.
Data exporting and sharing
No spatial data processing workflow is complete without addressing the essential requirement for sharing the outcome or results and, once again, Global Mapper is well-equipped for this task. Any collected or created data layers, regardless of format, can be easily reprojected and converted to meet the needs of the client. Cartographic layout tools are available for designing printed maps or for generating geospatial PDFs representing the project site. Global Mapper can even create a 3D PDF allowing anyone with a PDF reader to render a three-dimensional model of any 3D data. For UAV applications, one of the most interesting project visualization options in Global Mapper is the creation of a 3D flythrough. Created from the flight path of the UAV and, if applicable, integrating a video recorded during the mission, the display will render the video while following the flight progress on the 2D map. Even without the availability of an accompanying video, the 3D flythrough can be simulated using any loaded terrain or point cloud data and the 3D line feature that is used as the basis for the fly-through visualization can even be exported as a GPX file for use in the UAV’s navigation system.
Global Mapper has become an essential application for many research organizations and pioneering companies in the professional UAV field. As Global Mapper continues its evolutionary development, these users will play a pivotal role in shaping the software’s functional makeup to ensure it is meeting the needs of the UAV community at large. If you are not currently using Global Mapper, why not download a free trial copy.
David McKittrick is a Senior Application Specialist at Blue Marble Geographics in Hallowell, Maine. A graduate of the University of Ulster in Northern Ireland, McKittrick has spent over 25 years in the field of GIS and mapping, focusing on the application and implementation spatial technology. McKittrick has designed and delivered hundreds of GIS training classes, seminars, and presentations and has authored dozens of articles and papers for a variety industry and trade publications.