As president-elect of the American Association for Geodetic Surveying (AAGS), I participated in a joint quarterly meeting with the National Geodetic Survey (NGS), the National Society of Professional Surveyors (NSPS) and AAGS on April 25.
I invite you to visit the AAGS website and consider joining our monthly board meetings, which are held on the second Tuesday of each month. All are welcome to attend. If you are interested, email me at [email protected] to be added to the attendee list.
Now, for some updates from the joint quarterly meeting.
During the meeting, I provided an update on the Certificate for Geodetic Surveying program, which has been under development by AAGS and is expected to be available by the end of the year. The program is designed to meet the needs of surveyors and others that perform spatial analyses and computations using geodetic methods.
Tim Burch, executive director of the National Society of NSPS, wrote the following in an April 23, 2025, xyHt article:
“To the average professional surveyor, the term “geodesy” does not exist in their everyday conversations about the business. While the use of state plane coordinates has expanded greatly with the development of GPS/GNSS receivers and RTK/RTN connectivity, the mathematics and “black magic” of geodesy remains an enigma to most of the profession.
However, the ongoing progression of technology within surveying instruments has expanded the need for understanding how geodesy works. Our practitioners are faced with expanding their knowledge and expertise of geodesy and thus have put a new challenge on them to find teachers and/or mentors to provide training on the datums and techniques.”
This is exactly what AAGS is attempting to do with the Certificate for Geodetic Surveying program. The information below includes the program description and content. AAGS has developed a set of questions that will determine if an individual has demonstrated a minimum competence in understanding and applying geodetic surveying concepts. AAGS is working with NSPS, who will be administrating the program for AAGS. The status and updates of this program are provided at the AAGS Monthly Board meetings. Come join us to hear more about the program and other AAGS activities.
Certification for Geodetic Surveying
Program description and content. Certification for Geodetic Surveying is official recognition that a person has demonstrated to the satisfaction of the Certification for Geodetic Surveying Board that he or she is minimally competent to perform spatial analyses and computations using geodetic methods. It is not intended to certify scientists performing research in geodesy. Rather, it is for individuals who use geodetic concepts and techniques to solve practical problems as a part of performing their work. Typical practitioners include geodetic surveyors, geodetic/geomatics engineers, geospatial software developers, geographic information systems (GIS) professionals, and geospatial data managers. The focus is more on the use of applied geodetic methods than with a particular field. A person who has obtained the Certification for Geodetic Surveying is one who has demonstrated minimum competence. In this context, “minimum competence” is a combination of working knowledge and familiarity with geodetic concepts that shows the ability to understand and solve applied practical geodetic problems as normally encountered in modern geospatial practice. Importantly, this includes an understanding of one’s limitations in solving such problems.
The Certification for Geodetic Surveying Board will identify the depth of knowledge required to achieve minimum competence for Geodetic Certification in the following areas:
- Geometric geodesy
- Reference frames, reference systems, geometric datums, and realization strategies
- Characteristics of modern reference systems, including NAD 83, WGS 84, ITRF, and IGS
- Transformations between datums, both modern and historic
- Geodetic, projected, and local geodetic horizon coordinate systems
- Direct and inverse problems for geodesics and map projections
- Reference ellipsoids, radii of curvature, and types of geodetic and projected distances
- Reductions, conversions, and relationships between coordinate systems
- Transformations used to create “localization/calibration” coordinate systems
- Physical geodesy
- Gravity, “the” geoid, gravimetric and “hybrid” geoid models, physical height systems, deflection of the vertical
- Vertical geodetic datum definitions and transformations
- Types of heights and their relationships; conversions between the various types
- Terrestrial methods for vertical, horizontal, and 3-D positioning
- Geodetic leveling and height determination; leveling instrumentation and corrections
- Modern 3-D terrestrial methods and instruments, including total stations and scanners
- Familiarity with historical methods such as triangulation, trilateration, and geodetic astronomy
- Accuracy and error
- Positional error estimation and uncertainty propagation; statistics and probability theory
- Characterization using network and local accuracies, error ellipses, and confidence levels
- Temporal aspects
- Plate tectonics (both steady-state and episodic); plate-fixed versus no-net rotation reference systems; subsidence; isostatic adjustment; tidal deformation
- Time-dependent transformations between reference systems
- Global Navigation Satellite Systems (GNSS)
- Instrumentation; system architecture; signal structure; error budget
- Methods for position determination, including by pseudorange, differential correction, carrier-phase differencing, and precise point positioning
- Geodetic survey networks
- Design, adjustment, and analysis of GNSS and terrestrial geodetic survey networks
- Formulation and solution of least-squares network adjustments
- Standards and guidelines
- Official standards, specifications, and guidelines for geodetic control, positioning, and accuracy
- The US National Spatial Reference System and similar systems elsewhere
Many of you are probably aware of the actions taken by the current administration to reduce the size of the U.S. federal workforce, these actions may affect all users of U.S. geospatial products and services. NGS is not exempt from these actions; recently, they have lost many employees either though leaving service voluntarily, retiring earlier than planned, or having been terminated because they were still in the probation period of their employment. NGS leadership did not provide any details on changes in personnel; only time will tell what the loss of personnel will have with the agency in the future. That said, NGS’s plans still include transitioning the modernized NSRS Alpha Site to a Beta Site this year. The current alpha site has four products — State Plane Coordinate System. SPCS2022, NGS Coordinate Conversion and Transformation Tool (NCAT), Euler Pole Parameters (EPPs) and The North American-Pacific Geopotential Datum of 2022. My understanding is that all four of these alpha products will be transitioned to beta products sometime in 2025. Some may have limited options in the beginning.
During this period, the beta site will provide the content, format and structure of data and products that should not change much from the final product. There could be minor changes detected during the beta phase, but users should not anticipate large significant changes. That said, that is why you have a beta phase before production. It is important for users to access the beta products and identify any issues or concerns and provide feedback to NGS. Future newsletters will highlight the beta products as they are released.
Finally, I would like to highlight a NGS webinar held on April 25, “Design of Networks Using NOS NGS 92.” Dave Zenk, NGS Northern Plains Regional Advisory, gave a good presentation outlining the tables that users need to be familiar with using OPUS Projects to process and submit GNSS projects to NGS for publications. The webinar provided a few examples to explain the concepts. Users can download the webinar from NGS webinar website.
I found the webinar to be very informative, and I would encourage all users of OPUS Projects to download the presentation. During the webinar, Dave briefly mentioned three items that I believe deserve more explanation for anyone using OPUS Project. I will address the following topics in more detail in future newsletters:
- The mark’s classification — primary, secondary, and local – will not be included on the NGS datasheet but the local and network accuracy from the project will be provided on the datasheet. What does this mean to someone that’s using the mark in their project?
- OPUS Project uses the F statistic test to determine if the appropriate constraints were imposed during the horizontally and vertically constrained adjustments. Why does OPUS Project use this statistic?
- The Constraint Ratio (CR) test computed by OPUS Projects provides a way of identifying which coordinates should be constrained and which should not be considered for constraints in the final horizontally and vertically constrained adjustments. What’s the best way to use this table?
Again, I would like to invite you to check out the AAGS website and consider participating in AAGS monthly Board meetings. If you are interested in attending the meeting, send an email to me at [email protected].
Finally, users should continue to check NGS’s website for the announcement of the transition from the alpha site to the beta site. Future newsletters will highlight the beta products as they are released.
