Abstract: A scanning coherent lidar system based on rectangular grids was used to build a speed model of rotating targets. The theory of velocity features was studied, and its velocity spectrum matched the classic time-frequency spectrum. Velocity spectrum of precessing non-spinning cylindrical targets were calculated and simulated under different precession cone angles. Experiment results showed that simulation and experiment matched well. The proposed velocity feature spectrum enriches the speed model for rotating targets in scanning coherent lidar. It offers a new way to analyze and extract micro-motion parameters of rotating and precessing targets.