Agenda

Webinar instructions will be emailed 24-48 business hours before the date of the webinar. 

Please log into the webinar 15 – 30 minutes before start time.


Tuesday, September 23, 2025
9:00 am – 1:15 pm CDT


Agenda:
Presented by Thomas H. Meyer, Ph.D.

Gravity, Geopotential, and the Geoid

  • Gravity affects almost everything a surveyor does
  • Water flowing downhill is not the same as geometric separation
  • The quest for a perfect vertical datum
    • Mean sea level
    • Definition of the geoid
    • Definition of an orthometric height
    • Normal gravity
    • Gravity potential energy
    • Geoid models

Heighting Systems

  • Physical (geopotential) heights
    • Geopotential numbers
    • Dynamic heights
    • Orthometric heights
  • Geometric heights
    • Geodetic (aka ellipsoid) heights
      • NAD83 vs WGS84
    • Geoid heights
  • Leveling Orthometric correction for differential leveling

Orthometric Heighting with GNSS

  • Occupation times
  • Passive vs. active control
  • Error budget
  • Practical example

 

Webinar Instructions 
 
All attendees must log-on through their own email – attendees may not watch together if they wish to earn continuing education credit. HalfMoon Education Inc. must be able to prove attendance if either the attendee or HalfMoon Education Inc. is audited. 

Certificates of completion can be downloaded in PDF form upon passing a short quiz. A link to the quiz will be sent to each qualifying attendee immediately after the webinar. The certificate can be downloaded from the Results page of the quiz upon scoring 80% or higher. 

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Windows 10 or higher, macOS 11 or higher, Linux, Google Chrome OS 

Web Browser:  
Google Chrome (most recent 3 versions) 
Microsoft Edge (most recent 3 versions) 

Internet connection: 1 Mbps or better 

Hardware:  2GB of RAM (minimum), 4GB or more of RAM (recommended) 

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Credits

Engineers
4.0 PDHs

Land Surveyors
4.0 PDHs

PIE - Practicing Institute of Engineering
4.0 PDHs

 

Continuing Education Information

This webinar is open to the public and is designed to qualify for 4.0 PDHs for professional engineers and land surveyors in most states. Please refer to specific state rules to verify eligibility.

HalfMoon Education is an approved continuing education sponsor for engineers in Florida (Provider License No: CEA362), Indiana (License No. CE21700059), Maryland, and New Jersey (Approval No. 24GP00049300). HalfMoon Education is an approved continuing education sponsor for land surveyors licensed in Indiana (License No. CE10600325), and Maryland. HalfMoon Education is deemed an approved continuing education sponsor for New York engineers and land surveyors via its registration with the Practicing Institute of Engineering (PIE).

This webinar has been evaluated for compliance with NYS Mandatory Continuing Education requirements for professional engineers and land surveyors by the Practicing Institute of Engineering, and has been approved for 4.0 PDHs.

This webinar has been registered with the Florida Board of Professional Surveyors and Mappers for 4.0 continuing education credits. This webinar has been approved by the Missouri Board of APEPLSPLA for 4.0 PDUs.

Attendance will be monitored, and attendance certificates will be available after the webinar for those who attend the entire course and score a minimum 80% on the quiz that follows the course (multiple attempts allowed).

*On-Demand Credits*

The preceding credit information only applies to the live presentation. This course in an on-demand format is not pre-approved by any licensing boards and may not qualify for the same credits; please consult your licensing board(s) to ensure that a structured, asynchronous learning format is appropriate.

Speakers

Dr. Thomas H. Meyer, Ph.D.

Professor of Geodesy, University of Connecticut

Dr. Meyer is a professor in the Department of Natural Resources and the Environment at UConn’s College of Agriculture, Health and Natural Resources (CAHNR). He is a member of the American Society of Civil Engineers and the American Society for Photogrammetry and Remote Sensing, and he is a fellow and past president (2016, 2019) of the American Association for Geodetic Surveying. Dr. Meyer is a past president (2006-2007) of the Geomatics Society of New England (previously known as the New England Section ACSM) and a member of the editorial boards of the Journal of Surveying Engineering and Surveying and Land Information Science. Dr. Meyer earned his Ph.D. degree from Texas A&M University (College Station, 1998) where he was a research associate in the Mapping Sciences Laboratory. He was named a UConn Teaching Fellow (2015), and he has taught geomatics courses at the graduate and undergraduate levels in geodesy, geographic information science, digital terrain modeling, spatial statistics, and global navigation satellite system surveying. Dr. Meyer has authored an undergraduate-level geodesy textbook and numerous peer-reviewed papers about surveying and mapping, and he teaches professional education seminars for surveyors throughout New England and the United States.