针对甚长基线干涉测量天文观测、深空探测和空间阵列项目对高精度理论时延计算的需求,该文进行了高精度理论时延计算软件的具体实现。首先介绍了河外射电源和探测器理论时延计算模型;然后详细阐述了理论时延计算软件的系统架构及其具体实现;最后将该软件与DiFX软件和嫦娥工程甚长基线干涉测量软件的计算结果进行对比分析。比对结果显示:对于河外射电源,理论时延差最大为几百个皮秒;对于探测器,理论时延差小于2ns,这表明该软件能够用于地面验证试验。
High-precision theoretical time delay calculation is necessary in VLBI astronomical observations, deep space exploration and space array projects. In this paper, high-precision calculation software of theoretical time delay was developed. Firstly, the theoretical delay calculation models and algorithms of extragalactic radio sources and detectors were introduced; secondly, the system architecture and implementation of the theoretical time delay calculation software were described in detail; finally, the calculation results of the proposed software was compared with that of DiFX software and Shanghai Astronomical Observatory CE-3 VLBI theoretical time delay software. The comparative results showed that the maximum of theoretical time delay difference was up to several hundred ps for extragalactic radio source while 2ns for detector, which indicated that the proposed software applies to ground verification test.