Multistage Algorithm for Single-Channel Extended-Dwell Signal Integration

For small radar platforms, the increase in signal-to-interference-plus-noise ratio (SINR) needed to support effective operation must come through integration of target signal energy collected over a long dwell time. Conventional radar processing assumes a linear-phase signal model and utilizes Fourier-based methods to coherently integrate signal energy. Over an extended dwell, the target signal generally includes multiple nonlinear-phase components which limit the effectiveness of conventional methods. An algorithm is presented that estimates the linear- and nonlinear-phase components of the extended-dwell-time target signal in a multistage process. The combined phase components form the signal model used in a filter that achieves near optimal matching performance for extended dwell times over a wide range of target parameters. Results are presented for both noise-limited and clutter-limited environments. For the specific conditions discussed, typical increase in output SINR for a 500 ms dwell time is 12 dB over the conventional coherent processing methods.