Weak target line spectrum multi-frame coherent track-before-detection method

The invention relates to a weak target line spectrum multi-frame coherent track-before-detect method, and discloses a weak target line spectrum track-before-detect method based on multi-frame coherent integration. The method comprises the following steps of: 1, performing multi-frame coherent integration on passive sonar receiving data to obtain a measurement calculation value; 2, establishing a state equation containing a target existence indication variable; step 3, establishing a multi-frame coherent integral measurement equation according to coherence of signal phases in the multi-frame data; 4, deducing a likelihood ratio function based on multi-frame coherent integration and matched with the measurement equation; and step 5, obtaining a more robust target line spectrum detection tracking result by using a particle filter iterative algorithm in combination with the measurement calculation value in the step 1 and the multi-frame coherent track-before-detect models established in the steps 2 to 4. The meth