Comparative Analysis of Pressure Depth Conversion Methods for Marine Acoustic Datum Depth Constrained Positioning

The underwater positioning of marine acoustic datum is mainly based on the principle of spatial distance intersection positioning. As the limitation of the observation structure, the observation error is easy to accumulate in the vertical direction. If the accurate depth of marine acoustic datum can be obtained and used for depth constrained positioning, it will help to further improve the positioning accuracy of marine acoustic datum. The depth gauge based on the principle of pressure measurement has been widely concerned due to the advantage of autonomous depth measurement. However, the effect of pressure-depth conversion on the positioning error of marine acoustic datum under depth constraint has not drawn enough scholarly attention. This paper focuses on the evaluation of the pressure-depth conversion accuracy of different seawater physical models and conducts an experimental analysis based on Argo buoy data. The results of the experiment show that the TEOS-10 model has the highest conversion accuracy, and using accurate profile information of temperature, salinity, and pressure parameters to correct the depth data is helpful to improve the accuracy of marine acoustic datum positioning.