Surveyed GCPs

Surveyed GCPs are any point within a dataset that has its location captured in-person by some sort of GPS equipment. This can be a PIP or purpose-made target such as a checkerboard panel. There is a range of equipment and associate accuracies for capturing surveyed GCPs. At the least accurate, a phone can be used to capture the location of a GCP. Next, hand-held GPS systems can achieve accuracies around 3 meters. Finally, survey-grade GPS can be used to achieve accuracies in the centimeters. More information on different survey equipment can be found on https://water.usgs.gov/osw/gps/ .