Study Of Algorithms In Deinterleaving And Tracking Radar Signals With Pulse Repetition Intervals

It is a difficult problem to deinterleave the radar signals in electronic countermeasures. Conventional algorithms are mainly based on histogram including cumulative difference histogram (CDIF) and sequential difference histogram (SDIF). With the increasing complexity of radar signals, these algorithms cannot meet the practical demand. In this thesis improved algorithms are presented as follows: (1) An algorithm based on the detection of arithmetical series is presented to deinterleave radar signals with stagger PRIs, especially to those with high order stagger ones. But this algorithm is limited to the model of stagger PRI presented by Resnick; (2) An algorithm is presented to estimate the PRIs of radar signals with jittered PRIs based on stochastic dynamic-linear models. This algorithm fits radar signals with jittered PRIs well, especially when jittered amount is large. But to this algorithm, it is important to select initial value and the amount of computation is large; (3) An algorithm is presented to estimate the PRFs based on stochastic dynamic-linear models. (4) A new algorithm for selecting detecting threshold based on the wavelet theory is presented to the environment when pulse sequences distribute unevenly in the whole sampling time. The circuit of tracking system with PRI is also designed in this thesis. The circuit is based on the conventional delay-superposition algorithm realized by the Field Programming Gate Array (FPGA). The circuit makes it possible to deinterleave and track with PRI in real time.