一种频点裁剪算法在差分定位中的应用

Application of Frequency Clipping Algorithm in Differential Location

针对联合差分定位系统中,由于共视卫星数增长致使lambda算法搜索空间成倍增加,导致定位效率降低,甚至无法求解的问题,提出了一种频点裁剪算法。该算法首先剔除信噪比异常低的卫星频点,然后根据设定的定位频点数,筛除多余的、信噪比较低的频点,从而有效地提高了定位效率。模拟转圈定位测试结果表明:单历元定位周期从120ms下降到40ms,水平定位误差在毫米级,垂直误差在厘米级。即该算法不仅大幅提升了定位效率,而且对定位精度没有影响。

In the joint differential positioning system,the search space of the lambda algorithm is multiplied due to the increase in the number of common-view satellites,resulting in low positioning efficiency or even impossible to solve.Aiming at these problems,a frequency clipping algorithm is proposed.It firstly deletes the satellite frequencies with abnormally low SNR(signal-to-noise ratio),then accordingly to the set location frequencies,filters out the redundant satellite frequencies with low SNRs,thus to effectively improve the positioning efficiency.Test result of simulated rotating ring positioning decreases from 120 ms to 40 ms,the horizontal positioning error is in the millimeter level,and the vertical error is in the centimeter scale.That is to say,this algorithm not only greatly improves the positioning efficiency,but also has no effect on the positioning accuracy.