Submarine resource exploration system, transmission device, reception device, signal processing device, signal processing method, electrical exploration method, electromagnetic exploration method, and program

Patent metadata

Field	Value
Publication number	US-11099291-B2
Application number	US-201716312210-A
Country	US
Kind code	B2
Filing date	Aug 25, 2017
Priority date	Sep 9, 2016
Publication date	Aug 24, 2021
Grant date	Aug 24, 2021

Abstract

A transmission device of a submarine resource exploration system includes a transmission unit which transmits a predetermined transmission artificial signal transmitted in order to perform exploration of submarine resources in water using water as a medium. A reception device includes a reception unit which receives a composite signal of a received artificial signal representing a signal propagated to the reception device using water as a medium in the transmission artificial signal, and a self-potential propagated to the reception device using water as a medium due to a potential anomaly generated due to submarine resources. A signal processing device includes a signal processing unit which separates the composite signal into the received artificial signal and the self-potential.

First claim

What is claimed is:

1. A submarine resource exploration system comprising a transmission device, a reception device, and a signal processing device, wherein
the transmission device includes a transmission unit which transmits a transmission artificial signal representing a predetermined signal transmitted in order to perform exploration of submarine resources in water using water as a medium,
the reception device includes a reception unit which receives a composite signal of a received artificial signal representing a signal propagated to the reception device using water as a medium in the transmission artificial signal, and a self-potential propagated to the reception device using water as a medium due to a potential anomaly generated due to submarine resources, and
the signal processing device includes a signal processing unit which separates the composite signal into the received artificial signal and the self-potential,
the reception device, or the transmission device and the reception device are installed in a mobile body moving in water,
the reception device includes a plurality of electrodes which receive the composite signal, and the plurality of electrodes are separately disposed in the horizontal direction or in a vertical direction at predetermined intervals, and
the signal processing unit estimates a position corresponding to an inflection point of an electric field, which is indicated by a signal obtained by separating the composite signal, in a horizontal direction or a position corresponding to an extreme point of the electric field in a vertical direction as a position at which underground resources are buried.

2. The submarine resource exploration system according to claim 1 , wherein
the transmission device includes a first atomic clock, and a transmission data writing unit which makes a first association information of a current value of the transmission artificial signal associated with a time indicated by the first atomic clock and a position of the transmission device at a time when the transmission device transmits the transmission artificial signal and wherein the transmission device writes the first association information to a first data table of a storage unit at predetermined time intervals,
the reception device includes a second atomic clock synchronized in time with the first atomic clock, and a reception data writing unit which makes a second association information of a voltage value of a composite signal sampled by the reception unit at a predetermined time interval associated with the time indicated by the second atomic clock when the reception unit has sampled the composite signal and a position of the reception device when the reception unit has sampled the composite signal and wherein
the reception device writes the second association information to a second data table of a storage unit, and
the signal processing unit separates the composite signal into the received artificial signal and the self-potential on the basis of the data on the second data table written by the reception data writing unit to the storage unit.

3. The submarine resource exploration system according to claim 1 , wherein the signal processing unit separates the composite signal into the received artificial signal and the self-potential using a low pass filter.

4. The submarine resource exploration system according to claim 1 , wherein the signal processing unit separates the composite signal into the received artificial signal and the self-potential using polynomial approximation including the first order.

5. The submarine resource exploration system according to claim 1 , wherein the signal processing unit separates the composite signal into the received artificial signal and the self-potential on the basis of principal component analysis or independent component analysis.

6. The submarine resource exploration system according to claim 1 , wherein the signal processing unit separates the composite signal into the received artificial signal and the self-potential on the basis of the transmission artificial signal, a sine wave signal representing each frequency component included in the transmission artificial signal, and a cosine wave signal having a phase 90° different from the sine wave signal.

7. The submarine resource exploration system according to claim 1 , wherein the signal processing unit separates the composite signal into the received artificial signal and the self-potential using a high pass filter.

8. The submarine resource exploration system according to claim 1 , wherein the reception device includes a plurality of electrodes which receive the composite signal, and some of the plurality of electrodes are separately disposed in the vertical direction at a predetermined interval and other electrodes are separately disposed in the horizontal direction at a predetermined interval.

9. A signal processing device comprising: a signal processing unit which separates a composite signal of
a received artificial signal representing a signal propagated to a reception device, comprising a reception unit installed in a mobile body moving in water, using water as a medium in a transmission artificial signal representing a predetermined signal transmitted from a transmission device comprising a transmission unit installed at a predetermined position in water or installed in a mobile body moving in water in order to perform exploration of submarine resources, and
a self-potential propagated to the reception device using water as a medium due to a potential anomaly generated due to submarine resources into the received artificial signal and the self-potential, wherein
the reception device includes a plurality of electrodes which receive the composite signal, and the plurality of electrodes are separately disposed in the horizontal direction or in a vertical direction at predetermined intervals, and
the signal processing unit estimates a position corresponding to an inflection point of an electric field, which is indicated by a signal obtained by separating the composite signal, in a horizontal direction or a position corresponding to an extreme point of the electric field in a vertical direction as a position at which underground resources are buried.

10. A signal processing method comprising:
transmitting a transmission artificial signal representing a predetermined signal transmitted from a transmission device comprising a transmission unit installed at a predetermined position in water or installed in a mobile body moving in water in order to perform exploration of submarine resources in water using water as a medium;
receiving a composite signal of a received artificial signal representing a signal propagated to a reception device using water as a medium in the transmission artificial signal, and a self-potential propagated to the reception device using water as a medium due to a potential anomaly generated due to submarine resources, the reception device including a plurality of electrodes which receive the composite signal, and the plurality of electrodes are separately disposed in the horizontal direction or in a vertical direction at predetermined intervals;
separating the composite signal into the received artificial signal and the self-potential; and
estimating a position corresponding to an inflection point of an electric field, which is indicated by a signal obtained by separating the composite signal, in a horizontal direction or a position corresponding to an extreme point of the electric field in a vertical direction as a position at which underground resources are buried.

11. An electrical exploration method comprising:
transmitting a transmission artificial signal repre

Assignees

• Japan Agency Marine Earth Sci
• Nippon Marine Entpr Ltd
• Japan Agency For Marine Earth Science And Tech & Nippon Marine Enterprises Ltd

Inventors

• KASAYA Takafumi
• Goto Tadanori
• Kawada Yoshifumi
• Iwamoto Hisanori

Classifications

• G01V3/082 Primary

  operating with fields produced by spontaneous potentials, e.g. electrochemical or produced by telluric currents (G01V3/26 takes precedence) · CPC title

• G01V3/12

  operating with electromagnetic waves {(operating with millimetre waves G01V8/005)} · CPC title

• G01V3/38

  Processing data, e.g. for analysis, for interpretation, for correction · CPC title

• G01V3/08

  operating with magnetic or electric fields produced or modified by objects or geological structures or by detecting devices (with electromagnetic waves G01V3/12) · CPC title

• Y02A90/30

  Assessment of water resources · CPC title