Dually Supervised Track-Before-Detect Processing of Multichannel Video SAR Data

Track-before-detect (TBD) algorithm has been used to track weak moving target shadows in video synthetic aperture radar (SAR), where strong maneuverability may deteriorate tracking performance. Fortunately, the Doppler characteristic of the target can additionally provide velocity guidance for tracking. This article presents ground moving target indication (GMTI) results of the multichannel video SAR raw data, and a tracking approach is proposed based on the Doppler supervision in an improved dynamic programming-based TBD (DP-TBD) framework that uses a dual-domain merit function. Both the sequential high-resolution SAR images and low-resolution range-Doppler (RD) spectra are used, and the clutter in the RD spectrum is suppressed by using an adaptive displaced phase center antenna (ADPCA) technique. Fine states can be searched in dual-domain through resampling from random expansion in state initialization and transition. The inverse shadow amplitude and Doppler energy of the same potential target are simultaneously integrated to determine whether the target exists. The proposed Dual-DP-TBD can deal with the tracking of a time-varying number of targets in successive measurements. Compared to other TBD algorithms, this approach has fewer missing alarms and false alarms, thanks to precise velocity estimation constrained from diverse features both in SAR image and RD spectrum.