1. An apparatus for providing a rank threshold and regional rank for a radar system, the apparatus comprising: a signal processor configured to implement a spatially adaptive distribution free CFAR, said CFAR comprising a first processing channel and a second processing channel, said first processing channel being tuned for CFR gain in a spatially correlated background using a guard band of 1 or more cells and a background region of a plurality of cells and said second processing channel being tuned for low CFAR loss in a spatially uncorrelated background using a guard band having a number of cells greater than the number of cells in the guard band of said first channel and background region having a number of cells greater than the number of cells in the background region of said first channel; said CFAR further comprising a means of establishing a rank threshold in said first and second channel processing channel and a means of establishing a regional rank.