A Study on the Error Modeling of Differential GPS Correction

Abstract

After DGPS (differential global positioning system) correction, positioning accuracy is effected on correction accuracy and baseline between user and DGPS reference station. Correction accuracy is determined by estimated common error and extant non-common error. Estimated common error is occurred by not estimating ionospheric & tropospheric delay error, satellite clock error, and ephemeris error correctly. Extant non-common error is occurred by not removing measurement noise. This means that user and reference station have different errors in local area. So in order to develop UDRE (User Differential Range Error) estimation method to estimate positioning accuracy of navigation equipments using DGPS, it is necessary to analyze DGPS correction error. This paper analyzed DGPS correction error source. And it analyzed effect on correction error by raw measurement noise and baseline, and proposed a correction error model. Finally, this paper evaluated performance by comparing correction by the proposed correction error model with correction calculated in available off-the-shelf receiver for DGPS reference station.