EXTENDED RANGE DETECTION OF SEA-SURFACE TARGET BASED ON PRI-AGILE AND FREQUENCY- AGILE WAVEFORM

Due to the limitation of the maximum pulse width, the duty ratio of the low repetition frequency (LPRF) waveform is small when the maritime radar is detecting from a long distance, resulting in a loss of the maximum detection range. To solve this problem, this paper proposes an extended range detection technique of sea-surface target based on PRI-agile and frequency-agile waveform. The technique improves the duty ratio by transmitting a set of medium repetition frequency (MPRF) orthogonal waveforms, and resolves the range ambiguity based on the frequency-domain orthogonal characteristics of the echo signal, thereby suppressing the folding sea clutter. In addition, the pulse repetition interval (PRI) stagger processing is innovatively introduced to eliminate the fixed blind area of intra-frame detection and further improve the radar detection performance. The technique can effectively increase the integration number and extend the radar detection range under the condition of constant pulse energy.