An improved APIT localization algorithm for underwater acoustic sensor networks

Range-free localization algorithm is a cost-effective alternative for node localization in underwater acoustic sensor network because it requires no information about distance and angle, and only utilizes network connectivity to locate. Compared with other range-free localization algorithms, APIT (Approximate Point-In Triangulation) algorithm can achieve higher precision position estimation with small communication cost, however, the traditional APIT algorithm not only has heavy computing load but also an equivocal criterion. In this paper, we propose an improved APIT localization algorithm which changes the grid scanning into the point scanning. We also compare the improved APIT algorithm with the traditional APIT and the Centroid algorithm. It shows that collision affects location accuracy, and our algorithm performs better in the certain network load.