基于搜索算法的电离层模型参数计算方法

Calculational Methods for Ionosphere Delay Model Based on Search Arithmetic

电离层延迟是影响卫星定位精度的主要因素之一,使用准确的电离层延迟模型有助于提高卫星定位系统的精度。电离层延迟模型参数一般采用最小二乘法拟合得到,但是在实际工程中可能出现运算出错的情况。为了更准确地获取电离层延迟模型参数,给出两种搜索算法———松弛搜索法和随机搜索法,然后在分析两种算法优缺点的基础上,对搜索算法进行了改进,最后利用实测数据对提出的方法进行仿真。仿真结果表明,搜索算法避免了矩阵运算的困难,以及迭代初值对计算结果的影响,是电离层延迟参数计算的有效方法。

The impact of Ionosphere delay on satellite navigation cannot he ignored, and an exact Ionosphere de- lay model can help to improve the accuracy of positioning system. People usually use least squares method to get the fitting parameters, but in the practical engineering it may get wrong results. For getting the fitting parameters exactly, this paper presented two kinds of search arithmetics ~ relax iterative search and random search. Doing parameter fitting with actual Ionosphere delay date, this paper gave their advantages and disadvantages, and also told a useful im- proved means. The result presents that, search arithmetic avoids the impact of initial value and matrix calculation, and it is useful for getting the parameters of Ionosphere delay model.