研究了一种可用于着陆导航的全光纤线性调频连续波(LFMCW)-连续波(CW)激光多普勒雷达.以窄线宽激光器作为种子源，利用声光调制器对激光进行频率调制，通过平衡相干探测和基于FPGA的数字信号处理可实时获得航天器相对于天体的矢量速度.基于速度模拟发生器的实验结果表明，该多普勒雷达可获得高于0.05 cm/s的测速精度，同时具有速度方向辨别能力.

Precise determination of the relative velocity between the spacecraft and celestial body is necessary to ensure the secure landing in space exploration. An all-fiber linear frequency modulation continuous wave(LFMCW)-continuous wave(CW)Doppler laser radar was developed for landing navigation. A narrow line width laser was used as the seed laser. The laser frequency was modulated by an acousto-optic modulator. Speed vector was measured in real-time by means of balance coherent detection and digital signal processing based on FPGA. Experiments made on laser Doppler radar with a speed generator proved that 0.05cm/s or better accuracy can be achieved while the velocity direction can be discriminated.