GPS 广域增强系统(WAAS)建模及数字仿真

Modelling and Simulation of GPSWideArea Augmentation System(WAAS)

研究了一种ＷＡＡＳ的实现方案，主控站利用各基准站的观测数据估算ＧＰＳ卫星的三维星历误差、时钟误差的等效距离误差（包括ＳＡ误差）、电离层时滞参数及完好性信息，并将这些误差修正量及完好性信息发送给用户。仿真结果表明，利用这些ＷＡＡＳ校正量后，用户的定位精度可以得到很大的提高，并且定位精度在较大的范围内与用户的位置基本上无关。

The implementation of widearea augmentation system is studied.The master station can compute the threedimentional ephemeris errors,equivalent range errors of satellite clock offsets including SA errors,ionospheric time delay parameters and integrity information based on the information gathered by reference stations, and then the error corrections and integrity information is transmited to users.The simulation results indicate that the GPS position accuracy can be potentially increased by using the error corrections and does not varied with the user position on a larger area.