Design and Processing Method for Doppler-Tolerant Stepped-Frequency Waveform Using Staggered PRF

Abstract

Stepped-frequency waveform may be used to synthesize a wideband signal with several narrow-band pulses and achieve a high-resolution range profile without increasing the instantaneous bandwidth. Nevertheless, the conventional stepped-frequency waveform is Doppler sensitive, which greatly limits its application to moving targets. For this reason, this paper proposes a waveform design method using a staggered pulse repetition frequency to improve the Doppler tolerance effectively. First, a generalized echo model of the stepped-frequency waveform is constructed in order to analyze the Doppler sensitivity. Then, waveform design is carried out in the stepped-frequency waveform by using a staggered pulse repetition frequency so as to eliminate the high-order phase component that is caused by the target’s velocity. Further, the waveform design method is extended to the sparse stepped-frequency waveform, and we also propose corresponding methods for high-resolution range profile synthesis and motion compensation. Finally, experiments with electromagnetic data verify the high Doppler tolerance of the proposed waveform.

A Novel Velocity Estimation and Compensation Approach for Moving Target in Stepped Frequency Radar Based on Fractional Fourier Transform

“…It does not need estimation of the velocity and is easy to be realized. Referring to the opinion in [4], methods by using multiple stepped-frequency pulse trains and the robust phase unwrapping theorem to estimate the range and velocity of a target were introduced in [7,25]. These methods can well solve the range cell shift of the SFW radar.…”