高精度VLBI技术在深空探测中的应用
Application of High Precision VLBI Technology in Deep Space Exploration
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摘要: 介绍了适合单探测器测定轨的高精度VLBI技术和适合多探测器测定位的同波束VLBI技术的研究进展。利用"嫦娥3号"着陆器的ΔDOR型VLBI观测,得到了误差0.67 ns的VLBI群时延数据。利用"嫦娥3号"着陆器和月球车的同波束VLBI观测,得到了随机误差0.3 ps的差分相时延数据,以数厘米的灵敏度监测出月球车的移动、转弯等动作,并把月球车的相对定位精度提高至1 m。针对深空探测,提出了使VLBI时延测量精度进一步提高所需要开展的部分研究内容。Abstract: This paper reports the research progress of high precision VLBI technology used for single-spacecraft orbit determination and same beam VLBI technique used for multi-spacecraft position determination. The ΔDOR VLBI residual delay after determining orbit of Chang'e-3 Lander is 0.67 ns, and the error of differential phase delay between the Lander and Yutu rover of Chang'e-3 is down to 0.3 ps. By using the differential phase delay data, the rover motions such as movement and turning as small as several centimeters are monitored, and the relative position between the rover and the Lander is precisely measured with an accuracy of 1 meter. For deep space exploration, further research works are put forward to improve the VLBI delay measurement accuracy.