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

Tuesday, May 16, 2023 
8:30 am – 3:20 pm CDT


Presented by Thomas H. Meyer

Agenda Highlights

Accuracy and Precision: Expected Results and Observation-Session Duration

Observation modes (DGPS, Phase Differencing)


  • Ranging
  • GPS bands
  • Timing codes
    • Coarse/Acquisition code (C/A code)
    • Precise code (P code)
    • Navigation message, timing codes, code phase
  • Carrier phase
    • Inter-ambiguity problem: autonomous solutions, floating solutions, fixed solutions
  • Precise point positioning
  • DGPS
  • Code- and Phase-Differencing
  •  Static Positioning
    • CORS
    • Tripod, UConn HARN example
    • Range pole
  • Real-time positioning
    • Real-time kinetic (RTK), Real-time network (RTN)
  • RTN example: UConn class survey exercise


 Observation-Session Duration

  • Statistical independence
  • Autocorrelation and sampling interval
    • NGS example for heighting
  •   NGS occupation-duration CORS study


Error Budget

  • Range-pole centering error (Franklin and Meyer, SaLIS, 2016)
  • Multipath
  • Satellite constellation geometry
    • Dilutions of Precision (DoPs) (Meyer and Elaksher, Geomatics, 2021)
    • Why heighting is never as accurate as horizontal
  • Ionosphere, troposphere, signal-to-noise ratio


Background Information

  • Terms and nomenclature
  • History
  • GNSSs around the world
  • System architecture: Segments
    • Space, control, user


Ranging and Orbits

  • The range equation: multilateration
  • Orbits: the broadcast ephemeris


Geodesy Matters

  • The coordinate hierarchy
  • Antenna phase-center calibration: absolute vs. relative
  • Reference systems, reference frames, and datums
    • WGS84 vs NAD83
  • Time-dependent positioning, and stable reference frames
  • Geoid models and reference-frame choice
  • An eye toward the future 
    • North American Terrestrial Reference Frame vs WGS84 vs ITRF



 Webinar Instructions
Each webinar session earns continuing education credit and can be registered for individually. 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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Professional Engineers:
6.0 PDHs (in Most States)

Land Surveyors:
6.0 PDHs (in Most States)
(no credit for NY engineers or land surveyors)


Continuing Education Credit Information

This webinar is open to the public and is designed to qualify for 6.0 PDHs for professional engineers and land surveyors in most states, excluding New York. Please refer to specific state rules to determine eligibility. 

HalfMoon Education is an approved continuing education sponsor for engineers in Florida (Provider No. 0004647), Indiana (License No. CE21700059), Maryland, New Jersey (Approval No. 24GP00000700) and North Carolina (S-0130). 

 HalfMoon Education is an approved continuing education sponsor for land surveyors licensed in Indiana (License No. CE21700059), Maryland, and North Carolina (S-0130). This course has been registered with the Florida Department of Agriculture and Consumer Services (#10185). 

 HalfMoon Education has not applied to any state land surveyor boards not listed above that require pre-approval. Please consult the rules of your licensing board to determine eligibility. 

 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 may not be eligible for the same credits as the live presentation; please consult your licensing board(s) to ensure that a structured, asynchronous learning format is appropriate. 


Dr. Thomas H. Meyer Ph.D.

Tom Meyer was awarded a Ph.D. from Texas A&M University in College Station, Texas in 1998, where he was a research associate in the Mapping Sciences Laboratory. He now is a Professor of Geodesy in the Department of Natural Resources and the Environment at the University of Connecticut, where he teaches courses in geomatics, GNSS and plane surveying, geodesy, and geospatial analysis in Python. Dr. Meyer is a member of ASCE and the Connecticut Association of Land Surveyors. He is also a past president of the New England Section of the ACSM and a Fellow and the 2016/2019 president of the American Association for Geodetic Surveying. Dr. Meyer has published an undergraduate textbook on geodesy, numerous peer-reviewed journal articles, and is on the editorial boards of the Journal of Surveying Engineering (JSE) and Surveying and Land Information Science (SaLIS). He is a regular presenter at national meetings, giving workshops and seminars on numerous topics in geodesy, GNSS, and surveying. His most recent research projects include new formulations of low-distortion projections, and developing spatial statistical animal-movement models for mountain lions, bobcats, and salmon.

Streamable MP4/PDF Price: $329.00


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