Range–Doppler Resolution Enhancement of Ground-Based Radar by Data Extrapolation Technique

A method based on data extrapolation is proposed to enhance the range-Doppler (RD) resolution of ground-based radar. The method employs both the bandwidth extrapolation (BWE), a well-known range super-resolution technique, and the time width extrapolation (TWE), an interesting extension of BWE from the fast-time frequency to slow time, to construct the radar returns with larger bandwidth and more pulses. This method consists of two key parts: first performing TWE on the echoes after pulse compression and then performing BWE on the integrated echoes, which can bring better performance because the gain in radar signal processing is fully utilized. Not only this, an improved data extrapolation technique is designed and applied to the proposed method. The improvement is the generalization of the existing linear prediction-based extrapolation method and can ensure that radar resolution is further enhanced if a parameter of the suppression factor is set reasonably. The experiments based on the simulated data and the observations of vehicles on highway by an S-band ground-based radar illustrate that radar resolution can be improved by a factor of at least 3 with almost undistorted RD images and clutter narrowed in Doppler using a conservative suppression factor setting of $0.5\sim 1$ .