Signal processing of multi-frame stepped-frequency radar based on keystone transform

Keystone transform has been employed to remove range migration in high resolution range bins of moving targets among different stepped-frequency frames, and a new signal processing method using multi-frame stepped-frequency signals is analyzed and evaluated, with which high resolution range-velocity image of moving targets can be achieved. Theoretical analysis and simulation results showed that as long as parameters are properly designed, the method can achieve coherent integration of all moving targets between multi-frame stepped-frequency signals regardless of their unknown velocity. Moreover, thanks to great increase in coherent integration time, the capability of detecting small targets can be improved.