The bistatic space-based early warning radar (SBEWR) operates with a transmitting platform in geosynchronous orbit and a receiving platform in low earth orbit, thereby possessing many advantages such as antistealth, antijamming, resistance to destruction, and low-cost global detection. Compared with the airborne early warning radar, it faces more severe clutter range dependence due to the earth's rotation, leading to significant performance degradation when applying traditional space-time adaptive processing (STAP) to suppress clutter. To address this issue, this article proposes a cascaded frequency-diverse array (FDA) multiple-input–multiple-output (MIMO) STAP method to mitigate the range-ambiguous clutter in the bistatic SBEWR. Initially, the elevation–azimuth FDA-MIMO framework is proposed to enhance the discrimination ability of spatial frequencies of different ambiguous ranges. Then, the prefilters in elevation are designed to extract elevation mainlobe echoes. However, other range-ambiguous echoes also enter into the filters because the mainlobe width of elevation prefilters is constrained by limited array elements in elevation. Therefore, the azimuth prefilters are further devised to filter above induced undesired range-ambiguous echoes. After the aforementioned cascade prefiltering process, the clutter to be suppressed becomes approximately range independent and, thereby, can be effectively suppressed by the traditional STAP filter. In addition, the impact of nonorthogonal waveforms on the clutter suppression performance of the proposed method is also discussed in detail. Simulation results demonstrate the effectiveness of the proposed method from multiple perspectives.
Range-Ambiguous Clutter Suppression With Cascaded FDA-MIMO STAP for Bistatic Space-Based Early Warning Radar
IEEE Transactions on Aerospace and Electronic Systems ; 60 , 6 ; 7754-7770
2024-12-01
6685080 byte
Article (Journal)
Electronic Resource
English
Bistatic Space Borne Radar for Early Warning
British Library Conference Proceedings | 2006
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