THE BIAS EFFECTS OF EVEN MINOR GPS ERROR

Abstract:

The general consensus is that GPS receivers with sub-meter accuracy are necessary to correctly co-register ground plot data and lidar metrics. The reported effects of less accurate receivers are greater residual uncertainty in models of relationships but no substantive effects on the accuracy of large area estimates based on the model predictions. For two temperate forest study areas, one in Norway and one in Minnesota, the effects of GPS error on models of relationships and subsequent large area estimates were investigated using a combination of metrics obtained for plots located with GPS receivers with different accuracies and metrics associated with plots whose locations had been perturbed using simulation techniques. The results suggest that contrary to previously reported results, GPS error induces bias into estimation procedures.