摘要
用传统的差分GPS(DGPS)方法确定分布式SAR的星间相对位置,可能存在:(1)卫星的高速运动可能导致GPS接收信号的信噪比过低,进而造成可用信号数目无法达到正常解算的要求;(2)传统状态估计方法的精度不能满足要求。为解决上述问题,提出了一种基于增强型DGPS的相对定位样条方法,即在GPS测量的基础上,增加星间伪距测量,并结合待估参数的连续特性,建立了相对定位的样条模型,最后利用最小二乘进行参数估计。仿真结果表明:该方法的相对定位精度比相对传统方法大约提高了3倍。最后的理论分析验证了仿真的正确性。
When traditional DGPS methods are used to determine inter-satellite relative states of distributed SAR, there are two problems： （1） the high-speed movement of satellites can induce low SNR of GPS signal received, which makes that the numbers of feasible signals cannot meet the need of the algorithm; （2） the precision of traditional state estimation methods is not enough for this application. To solve the above problems, this paper proposes an augmented DGPS relative positioning method. This method adds inter-satellite pseudo-range measurements on the basis of GPS measurements, then founds a spline model of relative positioning based on the continuity of the parameters, finally uses the least - square method to estimation the parameters. Simulation results show that this method can improve relative positioning precision three times. The analyse in theory validates the correctness of the simulation results.
出处
《宇航学报》
EI
CAS
CSCD
北大核心
2007年第1期82-87,共6页
Journal of Astronautics
基金
国家自然科学基金(60402033)
全国优秀博士论文基金(200140)
