In this paper, a novel wireless sensor network discovery algorithm is presented which estimates the locations of a large number of low powered, randomly distributed sensor nodes. Initially, all nodes are at unknown locations except for a small number which are termed the "anchor" nodes. The remaining nodes are to be located as part of the discovery procedure. As the locations of sensor nodes are estimated, they can be used in the localization of other nodes. The locations of transmitting nodes are estimated in a decentralized manner by using a set of receiving sensor nodes at known or estimated locations within its coverage area to form an array. Initially a coarse localization of all nodes is performed to identify their approximate positions. A fine grained localization procedure then follows for enhancement. This paper will focus on the coarse localization approach. Simulations demonstrate the effectiveness of the proposed method.