Control Monuments (GPS)

John Chance Land Surveys, Inc. frequently uses established horizontal and vertical adjusted control monuments for various survey projects.

One area for locating monument information is the National Geodetic Survey (NGS) Data Sheet, a search and retrieval system posted by NGS on the Internet. NGS data sheets contain the latest monument information, descriptions, history, etc., and is updated by NGS on a regular basis. Searches can be performed either by monument name designation or by the radius area where the monument is situated.

The NGS data sheets also contain vital information necessary for GPS network adjustments such as ellipsoid heights, geoid heights, and monument classifications. Also included is whether the monument location is suitable for GPS observations, a time saver for the GPS Planner!