Data Characteristic Analysis and Experimental Research of BDS Differential Positioning Error

Abstract

The integrity of Beidou Satellite Navigation System (BDS) and its enhancement system is the key index to characterize the safe operation of navigation system and the key point of system performance evaluation. Aiming at the problem that the choice of the distribution model for integrity assessment needs data characteristics of positioning error as basis, this paper is based on the mechanism of positioning error and proposes to using the time series analysis method to analyze the characteristics of positioning error data of the BDS differential positioning from multiple angles of self-correlation, extremity and thick tail. And quantitative validation is also carried out by processing the actual positioning error data. The result shows that the differential positioning error shows the low correlation due to error cancellation which can satisfy the requirement of approximate independence of data for integrity modeling and evaluation. However, the positioning error shows thick tails in both vertical and horizontal directions. Compared with the normal distribution, the thickness tail of horizontal error is slighter, only 22.9% and the thickness tail of vertical error is heavier, reaching 60.7%. Combining the extreme value theory, the block maximum model describing the characteristics of sample thick tail is very suitable for the integrity evaluation of BDS.