Abstract: Due to the energy limitations of underwater acoustic sensor networks, low-complexity location algorithms are more suitable for underwater acoustic sensor networks. The traditional APIT algorithm can obtain better location accuracy with less control overhead, which is beneficial to the location of underwater sensor networks, but it has high complexity and large redundancy errors. This paper proposes a low-complexity APIT algorithm replaced the traditional grid SCAN algorithm with a point scanning method, and builds an underwater acoustic sensor network environment on the OPNET platform, and elaborates the implementation process of the location algorithm in underwater sensor network. Simulation results show that increasing the density of the unknown nodes and anchor nodes helps to improve the algorithm. The algorithm in this paper has higher location accuracy than the traditional APIT algorithm in the same condition.

Key words: underwater acoustic sensor networks, APIT algorithm, OPNET(Optimized Network Engineering Tool), the SCAN algorithm