In DGPS, measurement accuracy belongs to baseline. We performed simulations about long baseline DGPS in order to make sure the relation between a position of a reference station and measurement accuracy. We confirm that as baseline became longer, error average and 2drms became larger. Especially, 2-dimensional position of error average is located at opposite direction of the reference station. Thus we find that measurement accuracy belonged to not only baseline, but also azimuth of reference station in DGPS. We propose a new method using multiple reference stations in DGPS. We use three reference stations that surround user position in the latitudinal and longitudinal direction. In this method we use correction data of pseudorange from each reference station and calculate new correction data that belonge to baseline and azimuth of reference stations. We focus DGPS and aimed at realizing high accuracy measurement where a reference station does not exist at a short distance.

View full abstract

Real-time kinematic GPS (RTK-GPS) is a real-time satellite positioning system. Using RTK-GPS, the horizontal and vertical positions of an object can be determined to within a few centimeters. However, Japan currently lacks the essential infrastructure to support the consistent delivery of data. The authors developed and tested a FKP-method network-based RTK-GPS (FKP-RTK) positioning using the area correction parameter (FKP) via the Internet. We studied FKP-RTK positioning at a fixed point, while varying the position of the GPS reference station located inside the station network area. Both the precision and accuracy of the FKP-RTK positioning were confirmed to be independent of the position of the primary GPS reference station (PRS). Using an Internet line, as compared with a public phone line, comparable results were achieved. The degradation in positioning precision when compared to RTK-GPS positioning (non network-based) is not especially pronounced, and we can see that the results of the network-based RTK-GPS positioning correction results are high.

View full abstract