Study On Long-Term Integration Method For Detection Of Weak Target

With the rapid development of stealth technology and LPI radar, weak moving targets detection has been very important for radar. Key issue of weak moving targets detection under lower signal noise ratio is managing to enhance the target echo energy using long time coherent integration. It is simple to integrate the echo of static target, coherent integration or no-coherent integration can be straightly performed. However, for the echo of moving target, range migration due to the target travel in the Coherent Processing Interval (CPI) should be corrected before Long-Term integration.Firstly, this paper studies the coherent integration, non-coherent integration and the combination of coherent integration and non-coherent integration based on time-field and frequency-field compensation. Secondly, the principle of the Keystone transform is illustrated, with the discussion of the LFM echo signal model, the reason for range migration is introduced detailedly, and afterwards, three correction methods are proposed to implement the Keystone transform. Computer simulations are given to confirm the algorithms'validity. Finally, a novel method is put forward, which combines the Keystone transform and the coherent integration, and its effectiveness is proved via the simulation.