Colorado's Surveying USA Success

By Brian Dennis, PLS

The nationwide, NSPS event Surveying USA was held on March 19, the first of what is expected to be an annual event promoting land surveying. One participating group was the Colorado Spatial Reference Network (CSRN), representing Colorado on behalf of the Professional Land Surveyors of Colorado (PLSC).

The CSRN decided to highlight GPS for the land surveyor and showcase and compare Colorado’s Real Time Networks (RTNs). Colorado has two private RTNs, with Trimble VRS and Leica SmartNet supporting the Eastern Plains and a public network for the Western Slope provided by Mesa County and supported by Trimble.

With support and assistance from the Colorado Department of Transportation (CDOT), we were able to hold the event at the CDOT headquarters in Denver. We obtained GPS observations on the NGS monument TRANSPORTATION. This monument is routinely relied upon by local surveyors in the metro area, and we knew it would be a monument of interest to observe. We hosted approximately 120 attendees, ranging from land surveyors to scout troops, geocachers, students from Westwood College, and professionals from the National Geodetic Survey (NGS) and NSPS.

Our GPS network sponsors were Frontier Precision Inc., Hixon Mfg., Vectors Inc., Compass Tools Inc., and Rocky Mountain Lasers. Steve Parker with Boundary Stone, PC sponsored a hand-held GPS navigation course at the CDOT complex. The course was popular with the scouts because geocaching is a focal point with their activities. As a result, the scouts are now considering becoming part of our event and making the GPS navigation course a requirement for the geocaching badge.

Professional land surveyors from CSRN (easily identified with vests provided by CDOT) responded to questions and provided information about land surveying. In addition, each sponsor had a talking point regarding GPS for surveyors:
  • Frontier Precision (Trimble): GPS Static Observations and OPUS Solutions
  • Hixon Manufacturing (Leica): Survey Grade GPS
  • Compass Tools (Trimble): Mapping Grade GPS
  • Vectors Inc. (Trimble): Real Time Kinematics and Real Time Networks
  • Rocky Mountain Lasers (Topcon): Single Base Line Solutions
  • CSRN: The Land Survey Profession and the Community
Each sponsor demonstrated and discussed the GPS equipment and network capabilities specific to the manufacturer they represented, including discussions on GPS and geodesy in general and conceptually. All the sponsors and PLSs provided productive discussions, and the attendees engaged them with questions. The attendees were amazed at the GPS tools and the wide array of uses for GPS for land surveyors today. This allowed the public to see and hear that land surveying is much broader than construction staking. If not for the great sponsors and PLSs who participated and their willingness to speak about our profession, our event would not have been as successful, and we thank them.

The CSRN was supported by NGS through Pam Fromhertz (a CSRN board member and NGS Colorado state advisor), who presented a station to introduce the public to the NGS. This was a popular station also because attendees learned about additional spectrums of the survey profession and how surveyors play a role in a scientific environment.

As part of the event, NSPS requested that each state’s participants occupy and observe a monument with GPS from 11:00 a.m. to 11:30 a.m. to become eligible for the Guinness World Book of Records for simultaneous GPS observations. Frontier Precision began collecting a four-hour static observation data set at 7:30 a.m. and continued during 11:00 to 11:30 a.m., allowing our event and GPS observations to be included in the possible world record. This information was submitted to the NGS Online Positioning User Service (OPUS) and then provided to NSPS, to proceed to NGS for evaluation. NGS will be evaluating the GPS data set collected to see if the information can update the data sheet information/position for the monument observed or possibly be included in the next GEOID Model.

Once the four-hour static session concluded, we continued with additional GPS activities, such as RTK GPS network position comparisons. Each network sponsor was allotted 30 minutes to observe the monument with RTK GPS or mapping-grade GPS (which required post processing) and to capture a total of nine measurements each, with three measurements each at 15-second, 60-second, and 180-second intervals for position comparisons to the post-processed OPUS static session and the NGS data sheet, since TRANSPORTATION has an adjusted horizontal value.

We also want to evaluate with the RTNs if the position quality increased as the observation time increased and at what point the increased quality ceased or became nominal. We will be generating graphic representations of the results to be posted to the CSRN website at under the Industry Showcase section (or email us at For information on the national effort by NSPS, visit

Because the event was such a success, the CSRN voted to continue hosting it annually. We received 100% positive feedback from the attendees, and they are anxiously awaiting our next event (so are we).
Brian Dennis is president of Colorado Spatial Reference Network (CSRN).

About the Author

  • TJ Frazier, LS
    TJ Frazier, LS
    TJ Frazier is the magazine's editor for surveying and has more than 20 years experience in the surveying profession, currently as senior land surveyor for VanMar Associates in Mt. Airy, Md. He also worked in survey equipment sales for Loyola Spatial Systems, now part of Leica Geosystems. He earned a bachelor of sciences degree in business at Mt. St. Mary’s University in Emmitsburg, Md. He is married and has two daughters. Frazier can be reached at

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