Japan Oil, Gas and Metals National Corporation

Junzo Kasahara

Mamoru Takanashi

Yuki Nakamura

Yosuke Kunishi

Yoko Hasada

Ayato Kato

A survey method includes generating a first amplitude modulation signal by amplitude-modulating a carrier wave repeating the same pattern at a predetermined cycle in each of a plurality of vibrators with a modulation signal whose cycle is 1/m times the predetermined period and is different for each of the vibrators, transmitting the seismic wave based on the first amplitude modulation signal, generating a second amplitude modulation signal in one or more receivers, the second amplitude modulation signal being identical to the first amplitude modulation signal generated by any one of the seismic vibrators, generating a reception signal in each of the one or more receivers by receiving a synthetic seismic wave in which the seismic waves generated by the seismic vibrators are synthesized, calculating a correlation value between the reception signal and the second amplitude modulation signal, and analyzing characteristics of the medium on the basis of the correlation value.

Survey method, seismic vibrator, and survey system

A vibration detection system includes a seismic source device that generates a vibration wave repeated with a predetermined period, a vibration receiving device that receives a response wave due to the vibration wave transmitted via the ground, and a signal processing apparatus that processes measured vibration signals received by the vibration receiving device. The signal processing apparatus includes a separating part that separates individual periodic signals having a period according to a periodicity of the vibration wave generated by the seismic source from the measured vibration signals, the calculating part that calculates the standard periodic signal from the separated individual periodic signals, and the generating part that subtracts the standard periodic signal from the measured vibration signals and generates differential signals.

Vibration detecting system, signal processing apparatus and signal processing method

A signal processing device includes a propagation speed calculating means for calculating strength and a direction of vibration in an underground structure region using a calculation model including data of a vibration propagation speed; a simulated propagation speed calculating means for inputting seismic source information to a calculation model and calculating the strength and the direction of the vibration in the underground structure region using the calculation model; and an update amount calculating means for calculating an update amount to update the calculation model, on the basis of propagation speed distribution information and simulated propagation speed distribution information. The calculation model is a solid model, the propagation speed calculating means calculates strength and a direction of first vibration using a first measurement signal input to the calculation model and calculates strength and a direction of second vibration using a second measurement signal input to the calculation model.

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Tokyo, Japan

Mamoru Takanashi