Target detection in correlated clutter

Synthetic aperture radar (SAR) clutter may be characterised by its single-point distribution and its correlation structure both of which should be exploited in applications such as target detection. Use of the single-point distribution in target detection schemes is well understood and it is relatively easy to accommodate any particular assumed form for the distribution, such as the K distribution, in the formulation. However, use of the correlation structure is not so well understood and is hampered by the difficulties associated with analytical manipulation of general correlated distributions. In this paper a generic model for correlated radar clutter is proposed, based on a correlated Gaussian mixture distribution approximation to the clutter statistics in the log domain. Analytical manipulation of the model is possible since it is based on weighted sums of multivariate Gaussian distributions which have a tractable closed-form representation. The model is developed with reference to the target detection application although it is of more general importance.