月球VLBI关键技术研究

甚长基线干涉测量VLBI具有超高分辨率，在深空探测器测定轨、天体测量、天体物理广泛应用。VLBI分辨率为波长除以基线长度，地面基线长度受限于地球尺寸，空间VLBI为重要发展方向。在探月工程带动下，我们将利用月球中继星天线配备VLBI专用设备（致冷接收机、数据采集系统、星载氢钟）建成世界上首个月球轨道VLBI站。月地基线长达38万公里，世界上首次在如此长基线上观测，有望取得一系列原创性成果，但极富技术挑战性。故本项目将开展月球VLBI关键技术研究。主要研究内容有：月球VLBI数据处理技术。由于中继星处于月球大椭圆轨道，需开展中继星精密测定轨（由目前的100米提高到米级）、精密时延模型构造、多普勒补偿等研究。致冷接收机、数据采集系统等有效载荷的研发技术，特别是解决小冷量致冷接收机研发、星载高速数据采集和数据封装关键技术等。

VLBI has very high resolution and is widely used for astrometry, astrophysics and orbit determination in deep space exploration. VLBI resolution is wavelength divided by baseline length. Ground baseline length is limited by earth size, so space VLBI is an important approach. Driven by Chinese lunar exploration project, we will build the world's first lunar orbit VLBI station using the lunar relay satellite antenna with special VLBI equipment (cooling receiver, data acquisition system and on-board Hydrogen Maser). With a baseline of 380,000 km, the world's first observations at such a long baseline are expected to yield a range of original science results, but are extremely technically challenging. Therefore, this project will carry out the lunar VLBI key technology. The main research contents are: lunar VLBI data processing technology. Because the relay satellite is in lunar elliptical orbit, it is necessary to carry out precision orbit measurement (from the current 100 meters to the meter level), precision delay model construction, Doppler compensation. Carry out research on key technologies of payload development; specially solve the key technologies of development of cooling receiver under small cooling conditions , high-speed data acquision and data packaging technique.