IMAGING METHOD OF WATER PERMEABILITY IN DEPOSIT AND GROUND STRUCTURE CONTAINING UNDERGROUND FLUID, AND MEASURING METHOD OF PHYSICAL CHARACTERISTIC OF MEDIUM
PROBLEM TO BE SOLVED: To measure the physical characteristic of deposit correctly and clearly by converting the speed of pseudo randum acoustic signal after being incident and propagated into deposit and the image of attenuation following to a conversion formula, and obtaining an image showing the physical characteristic. SOLUTION: A piezoelectric vibration source 9 is incident an electric signal generated in a PRBS generator 3 and amplified by a power amplifier 8 into a measuring medium, and converts the signal into a propagated acoustic signal. The acoustic signal reflected from the medium is received with a multi-channel hydrophone array 12. The received signal reaches an A/D sub-system 5 through a signal regulating amplifier 11→a signal regulating filter 10, it is processed by a real time processor 4, and it is stored in a temporary memory device 6 or a large capacity memory device 7. A received signal data sent from the A/D sub-system 5 to the real time processor 4 is processed following to new conversion technique converting the pair of sound velocity and attenuation image due to transmitting and receiving of a series of acoustic signals to the pair of water permeability and porosity image.
