An Efficient Frequency-Domain Velocity-Filter Implementation for Dim Target Detection

An efficient Fourier-domain implementation of the velocity filter is presented. The Sliding Discrete Fourier Transform (SDFT) is exploited to yield a Track-Before-Detect (TBD) algorithm with a complexity that is independent of the filter integration time. As a consequence, dim targets near the noise floor of acquisition or surveillance sensors may be detected, and their states estimated, at a relatively low computational cost. The performance of the method is demonstrated using real sensor data. When processing the acquired data, the SDFT implementation is approximately 3 times faster than the equivalent Fast Fourier Transform (FFT) implementation and 16 times faster than the corresponding spatiotemporal implementation.