The article covers the review of methods and means of background return cancellation appropriate for Pulse-Doppler Pseudo continuous signal radars.
The peculiarities of Pulse-Doppler Pseudo-continuous Signal radars are specified in short. Further the generalized structures and peculiarities of work of multi-channel correlation-filtering signal processing in analog and digital implementation are considered. Attention is paid to that fact that during digital implementation of correlation-filtering signal processing nowadays the methods of cancellation of noise pulses are not used, that impairs interference immunity of processing chain, their Doppler characteristics and increases calculating consumption of digital signal processors. Author proposes to use a rejector comb filter in input before analog-to-digital converter which may be realized by means of compensation methods.
The structures and peculiarities of compensating rejector comb filters realized in analog and discrete (digital) types are considered in details. A new principle of formation of rejector comb characteristics of moving-target indication by using the compensator of digital filter of lower frequencies with periodically repetitive staircase phase characteristic in compensating channes is offered. It ensures a good form of all the combs of rejection and high “tabletopness” of comb characteristics of moving-target indication and also digital control of parameters of noise pulse rejection. This device allows compensating the noises on video freuencies and intermediate frequencies of acceptance reception path of coherent radar.
In conclusion the processes of cancellation of clutters in analog digital correlation filter channels and by means of discrete and digital compensators of moving-target indication are considered in details. The frequency, time, spectral characteristic of these processes are offered. The suitability of cascading compensators of moving-target indication for improvement of characteristics of noise pulses fejection and decrease of charging of digital processors of correlation-filter signal processing is described.