Direction-of-arrival estimation using the rank-revealing URV decomposition

An algorithm for updating the null space of a matrix is described. The algorithm is based on a decomposition, called the URV decomposition, which can be updated in O(N/sup 2/) and serves as an intermediary between the QR decomposition and the singular value decomposition. the URV decomposition is applied to a high-resolution direction-of-arrival problem based on the MUSIC algorithm. A virtue of the updating algorithm is the running estimate of rank.<<ETX>>