Space-time adaptive radar performance in heterogeneous clutter

Traditional analysis of space-time adaptive radar generally assumes the ide al condition of statistically independent and identically distributed (IID) secondary data. To the contrary, measured data suggests realistic clutter environments appear heterogeneous and so the secondary data is no longer II D. Heterogeneity leads to mismatch between actual and estimated covariance matrices, thereby magnifying the loss between the adaptive implementation a nd optimum condition. Concerns regarding the impact of clutter heterogeneit y on space-time adaptive processing (STAP) warrant further study. To this e nd, we propose space-time models of amplitude and spectral clutter heteroge neity, with operational airborne radar in mind, and then characterize expec ted STAP performance loss under such heterogeneous scenarios. Simulation re sults reveal loss in signal-to-interference plus noise ratio (SMR) ranging between a few tenths of a decibel to greater than 16 dB for specific cases.