NGS GPS on Bench Marks

Pick one that hasn't been observed yet

Dave Doyle mentioned this during his NJSPLS session. He urged surveyors to coordinate with their state geodetic advisors or associations to pick a benchmark that had not already been recently observed and logged. 😉
Mike

Pick one that hasn't been observed yet

FWIW,

As the name of the project indicates, make GPS observations on bench marks. Preferably points with valid NAVD 88 heights. Using points without these valid heights have less utility in the creation of the next hybrid geoid model.

Take a look at the file dseats.txt explains how NGS classifies benchmarks. A link to this file is provided whenever a data retrieval is performed. Intereating information, too often overlooked.

Also don't waste time making observations at heavily obstructed sites.

I worked on a project where we accepted data from user-chosen sites. We required a visibility diagram to be completed. One memorable site was completely obstructed up to about 80 degrees by trees. As expected, no good result could be obtained.

The project was intended to provide a uniform distribution of points throughout the state where each site was I observed in two separate days with six hour sessions. Unfortunately, our budget was large enough to reimburse observers at 100 sites but we obtained observations at less than 70 sites.

Looking at the distribution of GPS on Benchmark Points I see clusters rather than state-wide distribution.

Without either personnel or budget the NGS can no longert do this work. Relying on state-led efforts has not been successful. The states with the best networks get better; the worse are "free riders" benefiting from efforts of others.

I commend those planning to participate.

Cheers,

DMM

Pick one that hasn't been observed yet

Here in Arkansas, our GPS on Benchmarks has bee both in clusters and state wide. Our NGS Advisor is identifying pairs of benchmarks and having line checks run between them to verify that they have not been disturbed. Most of the leveling in our state was done in the 30's. We have 3 major lines that were run in the 90's. When I do GPS on Benchmarks, we try to get someone on a newer, believed to be stable Rod Marc then do simultatious observations on other benchmarks in the area.

We have a few holes in our GEOID Model and the only way to fix the May be a large leveling campaign. I don't know where the money for that will come from

I have been loading all of my GPS Observations into OPUS Projects. If they ever enable the share option the GPS on benchmarks and the new marks can all be adjusted.