WASS电离层网格算法在低纬地区的误差分析

对不同纬度的8个GPS观测台站得到的数据,采用广域增强系统(WASS)电离层网格算法计算了斜向电离层时延,并将计算结果同实际观测值之间的差别进行了统计分析.结果表明:在中高纬地区,WASS电离层网格算法的精度很高,但是在纬度较低的地区存在着较大的误差,产生这种误差的原因是由于低纬电离层中的电子浓度较大并且存在较大的经向梯度变化.为了减少这种误差,可以在低纬地区增加广域基准站的数量、缩小电离层单元网格的尺度等方法.

Error Analysis of WASS Ionospheric Grid Algorithm in Low Latitude Area

Though the data of eight GPS stations, the paper calculates slant ionospheric delay by using WASS ionospheric grid algorithm, and comparison is made between prediction values and observed ones. The results indicate that the algorithm prediction error is smaller in mid-high latitude than the one in low latitude because there is the high electric density and its longitude grads variety in low latitude area. In order to reduce the error, we can adopt the method of increasing number of wide reference stations and decreasing the size of ionospheric unit grads.