Constrained by orbital configuration and spectrum sharing,non-geostationary orbit(NGEO)satellites may be interfered when they are in the beam range of geostationary orbit(GEO)satellite.However,it is difficult for NGEO...Constrained by orbital configuration and spectrum sharing,non-geostationary orbit(NGEO)satellites may be interfered when they are in the beam range of geostationary orbit(GEO)satellite.However,it is difficult for NGEO operators to determine the signal source.Herein,we propose a method to locate the GEO signal source and estimate beam features,including beam pointing azimuth,elevation,and beamwidth,by the beam edge positions.We transform this estimation problem into two optimization problems by minimizing the estimation error,and solve both of them through a multi-variable joint iteration method with acceptable computation complexity.Numerical results show that when NGEO satellites pass through the beam twice,the longitude estimation error is about 0.01 degree,and the estimation results will be more and more accurate as the number of passing times increases.Besides,the proposed method is also effective when there are kilometer-level errors in beam edge positions.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.91738101)Shanghai Municipal Science and Technology Major Project(Grant No.2018SHZDZX04)Interdisciplinary Major Project of School of Information Science and Technology,Tsinghua University(Grant No.20031887521).
文摘Constrained by orbital configuration and spectrum sharing,non-geostationary orbit(NGEO)satellites may be interfered when they are in the beam range of geostationary orbit(GEO)satellite.However,it is difficult for NGEO operators to determine the signal source.Herein,we propose a method to locate the GEO signal source and estimate beam features,including beam pointing azimuth,elevation,and beamwidth,by the beam edge positions.We transform this estimation problem into two optimization problems by minimizing the estimation error,and solve both of them through a multi-variable joint iteration method with acceptable computation complexity.Numerical results show that when NGEO satellites pass through the beam twice,the longitude estimation error is about 0.01 degree,and the estimation results will be more and more accurate as the number of passing times increases.Besides,the proposed method is also effective when there are kilometer-level errors in beam edge positions.
文摘国产高空间分辨率卫星影像的几何定位精度一直是人们关注的热点问题。以GF-1和ZY-3卫星影像为研究对象,在分析检验有理多项式参数(rational polynomial coefficients,RPCs)存在的系统误差后,采用基于像面仿射变换的有理函数模型(rational function model,RFM)区域网平差方法消除单颗卫星立体影像对的定位系统误差;全面分析并评价了影像的几何定位精度,包括单景影像的定位精度、单颗卫星立体影像对的定位精度以及多星联合的定位精度;初步探讨了影响国产高空间分辨率卫星影像几何定位精度的主要因素,为实现国产卫星联合高精度对地观测提供参考。
