The emergence of underwater acoustic networks has greatly improved the potential capabilities of marine environment detection. In underwater acoustic network applications, node location is a basic and important task, and node location information is the guarantee for the completion of various underwater tasks. Most of the current underwater positioning models do not consider the influence of the uneven underwater medium or the uncertainty of the position of the network beacon modem, which will reduce the accuracy of the positioning results. This paper proposes an underwater acoustic network positioning method based on spatial-temporal self-calibration. This method can automatically calibrate the space position of the beacon modem using only the GPS position and depth sensor information obtained in real-time. Under the asynchronous system, the influence of the inhomogeneity of the underwater medium is analyzed, and the unscented Kalman algorithm is used to estimate the position of underwater mobile nodes. Finally, the effectiveness of this method is verified by simulation and sea trials.

The rapid development of underwater acoustic sensor networks(UASNs) will greatly improve people's ability to perceive and apply the ocean. The positional information of network nodes plays a vital role in UASNs system. Aiming at the problems of multiple access interference and location beacon selection in traditional location methods, this paper proposes a multiple access method combined with FDMA / CDMA, which optimizes the division of frequency band and orthogonal code resources according to the network topology to ensure that different beacon nodes send location signals with different frequencies and different orthogonal code compared, so as to realize conflict free multiple access of multiple location signals. This paper also proposes a network beacon autonomous switching method, which optimizes the transmission time of control command according to the position relationship between its own position and network nodes, updates the positioning beacon in real-time, and realizes the cross regional autonomous navigation and positioning of underwater mobile nodes. The method in this paper is verified by simulation and sea trial.