釜山에서의 Differential GPS의 測位精度

Abstract

This study describes the accuracies of position fixes observed by the DGPS system for the purpose of obtaining the utility basic data in the fishery and oceanography observation field. The circling experiments using the DGPS were made in water level point of National Fisheries University of Pusan and on the sea in Yongho bay located on the southeast of that university.

The main results are as follows:

1) The number of the usable satellites in standard fixed position were all eighteen, SC 2, 3, 11-21, 23-26 and SV 28 etc. Each satellites could be observed for average seven hours a day, and position fixing was found to be always possible except about thirty minutes. 2) In the standard fixed position, the radius of 95% probability circle and the shifted distance between the position fixes by the DGPS and true position were respectively 5.7m, 0.9m. In those above case ordinary GPS was respectively 48.8m, 54.2m. Therefore, the accuracy of the position fixed by DGPS was very higher than ordinary GPS. 3) At land, the shifted distance between the center of traces in the circling experiment of 15m radius by DGPS and standard position amounted to 5.5m and observed radius of circling traces was 17.5m. At sea, that distance between the center of traces in circling experiment of 20m radius by the DGPS and standard position amounted to 3.6m and observed radius of circling traces was 19.7m. Therefore, the utility of the circling experiment to obtain the accurate position fixes by the DGPS was found to very high.