On-farm-research protocols: determining vertical accuracy of differentially corrected carrier and code phase global positioning satellite systems

摘要

The objective of this study was to demonstrate an approach for determining the vertical accuracy of different global position satellite systems. Two hundred points were selected for comparison in a field with a gently rolling topography. The highestpoint was approximately 30 m higher than the lowest point. Elevation information from the differentially corrected GPS systems were compared with surveyed elevations. The regression equation between the local differentially corrected carrier phase receiver (y) and surveyed elevation (x) was: y =0.01+0.99x; r =0.99~**. Based on this analysis, the carrier phase receiver was not biased and the vertical errors were <2 cm. The regression equation between the Satellite differentially corrected code phase receiver and surveyed elevations (x) on different days were: y =-1.35+1.28x (r =0.82~**), and y=1.79+0.70x (r =0.78~**). These results showed that the differentially corrected code phase receiver produced inconsistent biased vertical measurements.