PIMA软件在APSG测地VLBI数据处理中的应用

Processing APSG Geodetic VLBI Data Using PIMA

上海VLBI相关处理中心引进了一款国外新近研发的VLBI相关后处理软件PIMA，它在相位校准、复带通校准和条纹搜索等方面具有独到的优势，特别适合于射电源的成图和绝对天体测量。以亚太空间地球动力学计划（Asian Pacific Space Geodynamics，APSG）测地VLBI观测为样本，介绍了PIMA软件及配套数据分析软件VTD／Post—Solve的特点和处理流程。对PIMA获得的观测量文件以及国际VLBI天体测量和大地测量服务（International VLBI Service for Geodesy and Astrometry,IVS）常规数据处理获得的观测量文件，分别进行了台站坐标和射电源位置参数解算。二者的解算结果在测量误差范围内一致，且在低信噪比情况下，PIMA获得了更多的观测量。后续的APSG观测将包括更多数量的微弱射电源。PIMA软件有望在此类数据处理中发挥重要作用。

Shanghai VLBI correlation center imported newly developed VLBI post- correlation software PIMA, which performs phase calibration, complex bandpass calibration and fringe search with advanced methods. By processing APSG geodetic VLBI data, we demonstrated the main characteristics and usage of the PIMA and related data analysis software VTD/Post-Solve. Based on the observation files deduced from PIMA and observation files used in regular IVS data processing respectively, we made data analysis in single session mode to estimate the positions of 11 stations and 14 radio sources. The comparison results show that the estimated results of station coordinates and source positions agree very well. We expect that the PIMA can play an important role in subsequent APSG observations which will include more weak radio sources.