Influence of the training set non-homogeneity on space-time adaptive processing performance in airborne pulse-Doppler radar
Radio engineering. Electronics. Telecommunication systems
Concern "Radio electronic technologies», 32, Nizhny Novgorod str., Moscow, 109029, Russia
One of the crucial issues for modern airborne radar systems is to provide all-aspect low scattering targets detection at maximum range. Currently airborne radar is equipped with two operational modes to meet this challenge: high pulse-repetition frequency for approaching target detection and medium pulse-repetition frequency for receding target detection. Although maximum detection range provided for receding targets is often insufficient because of the terrain clutter.
Significant improvement of radar characteristics could be achieved by using space-time processing. The adoption of space-time processing algorithms became possible due to the introduction of multi-input-multi-output phased array radars and progress of digital signal processing.
Since in practice all the required information about clutter background covariance matrix is unknown, space-time adaptive processing (STAP) is used. Clutter covariance matrix sample estimation is computed using training set composed of range bins that surround the cell under test. With that the surrounding range bins should contain similar interference to achieve STAP performance closed to potential (optimum). Although when the training set considers clutter background closed to altimeter its non-homogeneity increases.
The article contains performance analysis of STAP in multi-input-multi-output phased array radar when the training set composed of range bins considers clutter background closed to altimeter.
According to numerical analysis non-homogeneity of training set has least influence on the suboptimal STAP algorithm based on apriori knowledge of clutter characteristics for different bins. The algorithm significantly reduces (for 15-20 dB) clutter energy losses for low flying receding targets compared to conventional signal processing (at the same radar signal parameters) at sample support about 10-12. The level of the computational complexity of the algorithm allows its real-time hardware implementation.
Keywords:space-time adaptive processing, on board radar, multi-input-multi-output phased array, clutter suppression algorithm
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