针对使用伪距取整固定宽巷整周模糊度效率高,但是宽巷一周取整错误发生频繁,伪距误差较大时还会出现大于一周的取整错误的问题,设计了一种可以弥补宽巷取整错误的整周模糊度固定算法.通过宽巷分离出的L_1浮点解小数探测和修复宽巷一周取整错误,使用RAIM算法排除大于一周的宽巷取整错误,最后使用正确的整周模糊度固定全部整周模糊度,完成高精度定位.使用实际GPS超短基线数据比较该算法与单历元LAMBDA算法的性能.该算法提高了直接使用伪距取整宽巷整周模糊度的固定率.相比单历元LAMBDA算法,本文算法的固定率稍低,但计算效率有明显提升.
Carrier phase differential GPS has been widely used in ultra-short baseline situation such as orientation,attitude determination and deformation monitoring.Carrier phase integer ambiguity resolution is the key issue.It is efficient to round wide lane integer ambiguity by pseudo-range.However,the rounding error for one cycle wide lane integer ambiguity always happens,and when pseudo-range error is large,it may be more than one cycle error.In this work,an integer ambiguity resolution algorithm was designed to offset the wide lane integer ambiguity rounding error.One cycle wide lane integer ambiguity error was detected and fixed by the fractional part of L_1 float solution separated from wide lane.The wide lane integer ambiguity error beyond one cycle was excluded by RAIM algorithm.The whole integer ambiguity was solved by the baseline vector which was calculated by partial right integer ambiguity.Some field tests were carried out based on GPS ultra-short baseline.Results show that,the designed algorithm increases the success rate of directly rounding wide lane integer ambiguity.The success rate is slightly lower but the computational efficiency is much higher compared to single epoch LAMBDA algorithm.