1. A detection and ranging apparatus, comprising: a first array including plural sensors; a second array including plural sensors that are not collinear with the sensors of the first array except for one of the sensors that defines an origin of a spatial phase; and a signal processing unit configured to generate plural covariance matrices including a first covariance matrix and a second covariance matrix based on reflected waves received by the first array and the second array from targets, estimate first angles of the targets based on the first covariance matrix, reproduce an angle matrix based on the estimated first angles, perform triangular decomposition on a product of a generalized inverse matrix of the reproduced angle matrix and the second covariance matrix to obtain a matrix, construct a similarity transformation problem from submatrices of the obtained matrix, and estimate second angles of the targets based on the estimated first angles and solutions of the similarity transformation problem.