In today’s FORT 130 lab we tested the consistency of GPS measurements. At five selected points the initial UTM coordinate was recorded. Then an averaged waypoint with at least 30 measurements was recorded. The location difference or error was calculated in Excel. Below is a map of the test site.
The measurement of waypoints with GPS should be improved by averaging. The differences between the initial reading and averaged waypoint ranged from 2 to 18 meters, with an average of 7.5 meters.
Points 2, 3 and 4 were taken under forest canopies, although leaves have already fallen. Points 1, 5 and 6 were taken in open conditions. The differences were greater in open versus forest canopy conditions, although not consistently. The consistency results and calculations can be seen here: GPS-Consistency-Worksheet-Linehan.pdf.