Research on shallow sea multiple ocean bottom seismometer positioning with GNSS/acoustic technique and echo sounder

Abstract

Abstract: The Global Navigation Satellite System (GNSS) combined with acoustic technique has achieved significant economic benefits in oil exploration. During positioning of ocean bottom seismometers, hundreds of underwater transponders attached to seismometers are typically deployed. In order to improve the positioning accuracy of multi-sensor in shallow water, this paper analyses the ship GNSS data, Long baseline system (LBL) and single-beam bathymetric data, and presents the solution method of multi-target underwater acoustic positioning in shallow water with the depth constraints. Combined with the Natural Neighbor Interpolation (NNI) method, the regional elevation model is constructed, and the transponders elevation interpolation is performed in the horizontal position of robust estimation solution. According to the symmetry observation and the smooth terrain of the construction sea area, the bending error of the sound line is further eliminated by using the new piecewise incident model of the sound line bending to improve the plane positioning accuracy of the multi-target underwater in shallow water. Experiments in the South China Sea show that the new method model is more stable, has better anti-gross error performance, and effectively improves the accuracy of positioning under the condition of inaccurate sound velocity measurements and more gross errors of observation data.