All fiber coherent doppler lidar for space craft safe landing

Recent advances in fiber optic component technology and digital processing components have enabled the development of a new coherent doppler lidar (CDL) system based upon a fiber optic FMCW, which has small size and light weight. CDL can give high precision velocity measurements data and range measurements data which support space craft safe landing. We designed and implemented a CDL of all-fiber structure in this article. First of all, FMCW ranging theory was described. Second, the CDL architecture of the system was discussed. Last, we introduced radar fiber Coupling and signal processor part, which include signal acquisition hardware, signal processing of dedicated FFT based on FPGA. The experimental program and experimental results were presented in the paper. We analyzed the experimental results carefully. From the results, the project has the advantage of large velocimetry range (-100m/S~+100m/S) and high velocimetry accuracy (0.5%). It completely meted the requirement of Space Craft Safe Landing.