深空探测多目标VLBI跟踪与定位研究

The VLBI technique is characterized by geometric measurement, whose observation precision is free from kinetic model errors. The VLBI technique plays an important supporting role in orbit tracking and determination of spacecraft because its measurement is high in precision in tangential direction, which is complementary in information to range and Doppler techniques as high in precision in radial measurement. The positioning reduction of deep spacecraft depends only on the relative geometric relationship between the station network and the target, rather than restricted by the length of tracking arc nor the kinetic model error of forces exerting on the spacecraft, and so is of important application in the quick identification of spacecraft capture by the central celestial body and in the real-time monitoring of trace evolution during orbit maneuver of spacecraft. In this application several key issues concerning the positioning reduction of VLBI tracking to multi-spacecraft will be studied, including the calculation methodology and software development of geometric delay of the extragalactic radio sources in picosecond precision, which is a key step in the observation error correction of VLBI tracking data of spacecraft, the positioning reduction of VLBI tracking data of multi-spacecraft, which includes the mathematical model construction of differential VLBI observations, the positioning reduction of delay rate observations, the synthesized reduction of observations within some specified tracking arc and the resolve and removal of the ambiguity in the differential phase delay and delay rate. By carrying out differential VLBI observations of multi-spacecraft, combining with simulation analysis, and basing on the accumulation of knowledge in methods and software development as well as experience in engineering practice, to propose method, to research and develop practical software system, and to serve to lunar and deep space explorations as well as to scientific application researches, the application project is of great significance.

VLBI技术为几何测量，精度不受动力学模型误差的影响，具有横向测量精度高的特点，与测距测速技术视向精度高的特点形成信息互补，对空间探测器的测定轨具有重要支持作用。定位分析方法不受跟踪弧段长度、动力学模型误差的影响，仅取决于测站网与目标的相对几何关系，对捕获快速判断和轨道机动高精度实时监测具有重要应用。本申请将进行深空探测多目标VLBI跟踪与定位归算的数项关键问题研究，包括河外射电源几何时延皮秒级精度计算方法和软件研制，这是探测器VLBI跟踪资料误差修正的关键环节；多探测器VLBI跟踪定位归算，含差分观测模型构建、时延率定位和弧段观测资料联合解析与差分相位时延时延率模糊度去除等问题的方法研究和软件研制。开展深空探测器多目标差分VLBI观测，结合仿真分析，并基于定位归算方法与软件的知识和工程实践经验积累，提出方法、研发实用性软件系统，服务于探月和深空探测工程实践与科学应用研究，具有重要意义。

VLBI技术为几何测量，测量精度不受动力学模型误差的制约，具有横向测量精度高的特点，与测距测速类技术视向精度高的特点形成信息互补，对空间飞行器测定轨具有重要技术支撑作用。定位分析方法不受跟踪弧段长度、动力学模型误差的影响，仅取决于测站网与观测目标的相对几何关系，对捕获快速判断和轨道机动高精度实时监测具有重要应用。本项目研究深空探测多目标VLBI跟踪观测定位归算方法和软件，在河外射电源几何时延皮秒级精度计算方法和软件研制，多探测器VLBI跟踪定位归算与应用，黄道带河外射电源加密观测，VLBI测站本地连接测量等方面展开研究，获得重要进展，服务于探月和深空探测工程实践与科学应用研究，具有重要意义。