Meshless DOA estimation method based on L-type co-prime array

The invention discloses a meshless DOA (Direction of Arrival) estimation method based on an L-shaped co-prime array. According to the method, conjugate augmentation of an original co-prime array is realized by using the conjugate symmetry property of a cross-correlation function of physical array element receiving signals at different time intervals, and holes in a virtual conjugate augmentation array are interpolated by using the idea of atom norm minimization in a meshless method, so that the time interval of the cross-correlation function of the physical array element receiving signals is reduced. A covariance matrix of a virtual uniform linear array is obtained by solving a positive semidefinite programming problem, then unitary transformation is performed on the matrix, estimated values of an azimuth angle and a pitch angle are obtained through an ESPRIT method, and then a cost function is designed by utilizing different powers of different signals to realize matching of the azimuth angle and the pitch a