多种空间大地测量技术内综合方法研究及精度分析

摘要

详细地叙述了国际空间大地测量技术服务组织ILRS(International Laser Ranging Ser-vice),IVS(International VLBI Service),IGS(International GNSS Service)和IDS(International DORIS Service)分别采用SLR(satellite laser ranging),VLBI(very long baseline interferome-try),GPS(global positioning system)和DORIS(Doppler orbitography and radio-positioning intergrated by satellite)四种技术,并由多家分析中心的站坐标和地球定向参数的SINEX(solu-tion in independent exchange format)周解(或24 h 观测解)进行技术内综合解算的方法,包括技术内综合模型的建立、参考架基准约束问题和不同分析中心解的定权方法等主要内容,并对ILRS,IVS,IGS 和IDS 提供的技术内综合周(日)解的长期序列进行了站坐标和地球定向参数(earth orientation parameters,EOP)的精度评估,分析了地球参考架基准参数的长期特性.由地球参考架基准定义可知,SLR 技术内SINEX 综合解相对于ITRF2014 的平移参数时间跨度最长,且没有明显的偏差或漂移;GPS 技术的三个方向平移参数虽然弥散度最低,但是在X 方向和Y 方向存在长期的线性变化,在Z 方向存在跳变;DORIS 技术也有类似GPS 技术的现象.这些结果说明ITRF2014 选择SLR 定义的地心作为参考架原点是有道理的.通过分析台站坐标精度可知,利用各种技术对核心站和非核心站进行区分非常重要,所分别得到的精度有明显的不同.由于GNSS(global navigation satellite system)台站多且分布广,因此地球定向参数的确定精度要高于其他三种技术.%In this paper,we described in detail the intra-technique combination methods of international space geodesy technology services such as ILRS,IVS,IGS and IDS for SLR,VLBI,GPS and DORIS respectively.The combination is based on the SINEX weekly solu-tions or 24 h session solution(for VLBI)about the station positions and the earth orientation parameters(EOPs)from various analysis centers.The method mainly focused on the estab-lishment of the intra-technique combination model,constraint problems of reference frame datum definition,the re-weighting of different analysis center solutions and so on.Then,the accuracy of the station coordinates and EOPs of the intra-technique combination solutions from ILRS,IVS,IGS and IDS were evaluated and the long-term characteristic of the reference frame datum definition was analyzed.From the perspective of datum definition,the transla-tion of SLR intra-technique combined SINEX series w.r.t the ITRF2014 has no significant bias and drift with the longest time-span; the series of the GPS intra-technique combined weekly solutions have the smallest scatters in the translation w.r.t.the ITRF2014 but have drifts in X and Y translation and jumps in Z translation; it is similar for the DORIS intra-technique combined solutions as that of GPS.From the perspective of the station coordinates'accuracy,the distinguishment of the core and non-core stations is of great importance.Moreover,due to the good global distribution of GPS stations,the EOP from GPS is more accurate than that from other techniques.