The generalized likelihood ratio test detector (GLRTD) for the airborne MIMO radars was studied in the paper.It is well-known that the GLRTD performs poorly in the case of limited secondary data.To settle this problem

the GLRTD with diagonal loading (LGLRTD) was proposed exploiting the low-rank property of MIMO radar clutter subspace and the diagonal loading techniques.The closed-form detection probability and false alarm probability were derived.To reduce the computational load of the proposed detector

a simplified detector was introduced by considering the block-diagonal property of the clutter covariance matrix.Theoretical and simulation results showed that the proposed detectors had CFAR with respect to the covariance matrix of clutter

and were superior to the conventional GLRT detectors.