u2212 k 1 where dtr r 0 03 in the doa estimation dtr r 0 02 in the eds modeling and initially k k m 1 but to cope with casual trends of the ratios r k with k u2266 k m corresponding to the noise subspace after that in a programming loop for k k m 1 the threshold tr r is updated every time when r k lt tr r the signal subspace dimension k is determined using an introductory value k 0 and a programming loop for k 1 k m where if r k lt tr r is found the determination of k is ceased otherwise if the nat variable v k r k k v r k u2212 r k 1 that is tuned by the coefficient k v to enhance the gap between the subspaces is above the threshold tr v tr r dtr v with a tuning offset dtr v k is set equal to the current index k the tuning parameters for the nat variable v k and its threshold tr v are k v 0 75 dtr v 0 03 in the doa estimation and k v 0 67 dtr v 0 1 in the eds modeling where larger.