Design and implementation of microwave landing radar for Chinese Mars probe

The microwave landing radar provides the GNC (guidance, navigation and control) sub-system with the range and velocity relative to the Martian surface during the EDL (entry, descent, landing) phase, to ensure the safety for mars landing rover. Microwave landing radar adopts a linear frequency modulation continuous wave(LFCW) system and is equipped with four radar beams, each of which can measure range and velocity at the same time. Continuous wave radar has the characteristics of no blind range and high measurement accuracy. However, due to the leakage of transmission and receiving, the range will be limited, and the bottom of landing rover can cause multi-path problems and special sand and dust effect ,to the microwave landing radar system design brings many problems. In order to meet the requirements of far-range and highaccuracy, and be responsible for the range and velocity measurement in the mars environment, the microwave landing radar adopted high isolation system design and multi-path suppression algorithm, and carried out radar performance verification under various environments such as sand and dust, which effectively solved the problem of continuous wave radar and ensured the complete success of China's first mars exploration landing on the surface of mars.