Clutter Rank of Sparse Linear Array Radar

Severe clutter existing in airborne and spaceborne radar systems makes the moving target indication (MTI) mission a big challenge. To suppress the clutter effectively, the rank of clutter covariance matrix (termed as clutter rank) should be well understood. In dense array radar systems, it is found that the clutter rank can be estimated by the bandwidth-aperture product. This methodology is also applicable to sparse array radars, as long as the effective length of the equivalent array is correctly computed. In this paper, a general formula is presented to estimate the clutter rank of the system using linear arrays, and sequentially, the sufficient condition of full-rank clutter is given. The simulation shows that the general formula is accurate in various circumstances