The multistep sparse technology (MST) is described in this paper. Using multistep amplitudes (including 0 and 1) the prescribed array can be thinned. Compared with the statistic density tappering technology (only using 0 and 1 )
MST can improve the sidelobe level of the sparse array obviously. Here
with the help of the Probability Theory and the Optimum and Consistent Aproaching Method
MST is presented in details and the probability of the peak sidelobe level less than the given value is given.