A New Very Long Baseline Interferometry Method Based on the Uplink Signal

Very long baseline interferometry (VLBI) is widely used for astronomical observations and navigation of deep space receivers. To solve the problems of the downlink signal being excessively weak to be received and the excessively large acquisition time, a new VLBI measurement method based on the uplink signal is proposed. Deep space ground stations can provide radio measurement signals for deep space spacecraft via the uplink. The range, Doppler and VLBI can be determined by the spacecraft through signals from multiple ground stations. In this manner, a higher signal to noise ratio (SNR) can be obtained. This study involves the development of a prompt acquisition algorithm for high dynamic deep space signals. Furthermore, the measurement and tracking of the phases of multiple VLBI stations by deep space receiver employing the uplink are analyzed. The use of the algorithms reduce the acquisition time for deep space receiver, and high precision results can be obtained for the VLBI measurement. Compared with the traditional VLBI method, the ranging error on the same distance is effectively improved, and the angle measurement accuracy is better than delta differential one way ranging (ΔDOR). Because multiple spacecraft are not needed, there are fewer limitations than same beam interferometry (SBI).