Abstract:Radial velocity is an important parameter for modern radar to measure target characteristics, and improving its accurate measurement capability is one of the important research directions in the field of aerospace measurement and control. In fact, a monopulse radar usually integrates the functions of distance , speed, angle measurement. The selected repetition frequency is not enough to make the radar speed measurement without ambiguity, so the resolving velocity ambiguity must be performed. The resolving velocity ambiguity method based on the invariant embedding method is more mature, but the defuzzification time is relatively long. The variable repetition frequency method can effectively solve the velocity ambiguity to obtain accurate values, but it is proved by experiments that the variable frequency operation does not meet the requirements of the multi-station working mode commonly used in space launch sites, and it is easy to cause signal blockage and lead to the failure of velocity ambiguity resolution. On the basis of the traditional spectral peak search method, the improved variable-step spectral peak search method changes the search step size through regional search, searches seven times in the single-station working mode to obtain the region where the spectral peak is located, and uses the even symmetry property of the spectrum to effectively Reduce the impact of system noise, greatly improve the speed of understanding, fuzzy efficiency and accuracy. The variable-step search algorithm has more advantages than the traditional search algorithm in the mode of multi-station operation.