A device and method for measuring gravity near the seabed

Abstract

The invention relates to the technical field of marine gravity measurement, in particular to a gravity measurement device and a measurement method near the seabed. The device includes a submersible docking base, a relative gravimeter, a relative gravimeter carrying mechanism and an absolute gravimeter reference station. The docking base of the submersible is fixedly connected with the submersible, and the docking base of the submersible is detachably connected with the carrying mechanism of the relative gravimeter. The relative gravimeter is fixed on the relative gravimeter carrying mechanism, and the relative gravimeter carrying mechanism is detachably connected with the absolute gravimeter reference station. The absolute gravimeter reference station is provided with an absolute gravimeter and a relative gravimeter carrying mechanism docking base. The method includes near-bottom gravimetric measurements using the apparatus described above. The invention is less affected by wind and waves, can guarantee the stability of its posture, has enough time to realize static stability, can realize the comparison of reference points directly under water, and ensures the accuracy of measurement data.

Description

technical field [0001] The invention relates to the technical field of marine gravity measurement, in particular to a near-seabed gravity measurement device and a measurement method. Background technique [0002] Ocean gravity measurement is one of the marine geophysical measurement methods. Gravity measurement is theoretically based on Newton's law of universal gravitation, and takes the gravity change caused by the density difference of the various rock layers that make up the crust and upper mantle as the premise. The gravity field value of the earth's waters is measured by special instruments, and the distribution characteristics and changes of gravity anomalies are given. Laws, and then study the geological structure, crustal structure, earth morphology and exploration of seabed minerals. [0003] There are usually two ways to measure the existing ocean gravity. One is to sink the gravimeter into the seabed for telemetry, that is, the near-seabed gravity measurement, w...

AI Technical Summary

Problems solved by technology

The second is to place the gravimeter on a ship on the sea surface for observation, but this method is affected by various disturbances due to the movement of the measuring ship and the influence of sea water

When the two kinds of gravimeters are working, they also need to keep their attitudes as stable as possible. Unstable attitudes will lead to data inaccuracy and even instrument damage.

[0005] At present, the near-sea gravity measurement has applied the miniaturized relative gravimeter on the AUV for near-sea gravity measurement, but there are the following problems: 1. During the process of surfacing, diving, release and recovery of the AUV, due to the wind and waves on the water surface The impact cannot guarantee its attitude stability

2. The AUV and the relative gravimeter are fixedly installed. Since the AUV itself adopts the energy mode of its own battery, it cannot be stabilized for a sufficient time after reaching the bottom of the sea.

3. At present, ship-based absolute gravity meters or land gravity reference points are mostly used for data comparison. The reference points are far away from the survey area, so it is difficult to guarantee the accuracy of the data

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