Miss Distance Estimation Based on Scattering Center Model Using Time-Frequency Analysis

In the traditional miss distance (MD) estimation, Doppler frequencies of radar echoes are used to estimate MD by curve fitting, which is based on the signal model of a single scattering center. Actually, scattering responses of an extended object are contributed by a series of scattering centers. Moreover, the attributes (i.e., amplitudes and locations) of scattering centers of different types change with the aspect angles of the measuring radar. The multiple scattering centers and their different attributes make the characteristics of Doppler frequencies quite complex, and subject the traditional MD estimation method to serious error. To tackle this problem, a parametric scattering center model is built to precisely characterize different types of scattering centers, and the primary characteristics of Doppler frequencies corresponding to various scattering centers shown in time-frequency representation (TFR) are used to estimate MD by image fitting. The performance of this method has been validated, and results show that this method is of high accuracy even in low signal-to-noise ratio (SNR).