Land Use Academy

GPS Benchmark at Haddam Meadows State Park

A benchmark was installed during the summer of 2006 at Haddam Meadows State Park. The benchmark, which is in an open area with a clear view of the sky, can be used to test the accuracy of GPS receivers. You can download a PDF map with benchmark coordinates or you can take a Google Earth tour and view the benchmark's location.


A hole was dug to a depth of 1 meter. It was filled with concrete and the benchmark, along with a meter length of rebar was inserted into the mixture.

Dr. Tom Meyer, Department of Natural Resources Management and Engineering, College of Agriculture and Natural Resources, established the benchmark's coordinates using survey-grade GPS equipment.

Collecting GPS fixes

A Garmin GPS receiver was set to record points every 2 seconds. A second unit was set to record points every 5 seconds. A plot of these points shows the scatter of fixes over time and demonstrates the accuracy and precision of the units. Click here to learn more about test results.