Relocation method of ocean bottom seismometer based on time slice method

Abstract

The invention discloses a relocation method of an ocean bottom seismometer based on a time slice method. The method includes following steps: 1) picking a direct wave travel-time of each shot point, and extracting a horizontal coordinate value of each shot point; 2) extracting a horizontal coordinate of each shot point aiming at a certain time slice, and performing circle fitting by employing the least squares method; 3) solving the center of circle, wherein the center of circle refers to the horizontal coordinate, inverted by the time slice, of the ocean bottom seismometer; 4) selecting other time slices, and inverting a series of horizontal coordinates of the ocean bottom seismometer according to the steps 2) and 3); 5) averaging the series of inverted horizontal coordinates of the ocean bottom seismometer, wherein the average coordinate refers to the finally inverted horizontal position of the ocean bottom seismometer; and 6) after inversion of the horizontal position of the ocean bottom seismometer, inverting the depth of the ocean bottom seismometer in the seawater and the propagation speed of seismic waves in the seawater by employing the idea of scanning. Compared with a five-point location method, the method is more accurate.

Description

technical field [0001] The invention belongs to the technical field of geological exploration, and in particular relates to a method for relocating a seabed seismograph based on a time slicing method. Background technique [0002] In the exploration of Ocean Bottom Seismometer (OBS, Ocean Bottom Seismometer), the OBS is dropped to the bottom of the sea in a free-fall manner. Due to the influence of the ocean current during the descent, the actual position of the OBS on the bottom of the sea may deviate from the design point (deployment position ). Therefore, it is necessary to perform secondary positioning of the OBS on the seabed based on the collected data. The initial position can be accurately positioned by GPS, but after launching, the geophone cannot receive GPS signals underwater, and this method cannot be used for relocation, but the accurate position of the underwater OBS can be calculated based on the collected data information. [0003] Gas hydrates are located ...

AI Technical Summary

Problems solved by technology

However, since the speed of seismic waves propagating in seawater changes with changes in water depth, water temperature and other factors, the positioning accuracy of the five-point relocation method is restricted and it is difficult to improve

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