Redundancy Generation and Elimination Method for Range Estimation in Stepped Frequency Radar

In order to adapt to the crowed High Frequency (HF) electromagnetic environment, improve the utilization rate of bandwidth and further realize the higher range resolution, the sparse random stepped frequency (SRSF) signal is introduced into HF radar. Signal model based on compressive sensing (CS) theory is put forward to reconstruct the range spectrum of targets. However, redundancy is generated due to external factors or unreasonable parameters in the process of estimating. Therefore, in this paper, key external factors affecting the range estimation performance are analyzed in detail. These factors mainly include mismatched distance redundancy, oversample redundancy, and also distortion from unknown velocities of moving targets. Specific elimination methods are also provided. Comparison between before and after elimination shows the effectiveness of the proposed method.