SEISMIC IMAGING SYSTEM FOR COUSTIC-ELASTIC COUPLED MEDIA USING ACCUMULATED LAPLACE GRADIENT DIRECTION

摘要

PURPOSE: An underground visualization system is provided to improve the restoration of a structure such as a dome in an abyss structure and to suppress the deformity related to irregular surface of the sea bed. CONSTITUTION: An underground visualization system includes a scaled gradient calculation unit (310), a repetition control unit (350) and a modeling parameter update unit (330). The scaled gradient calculation unit calculates a scaled gradient direction of the objective function by multiplying an accumulated gradient value to the original gradient value. The accumulated gradient value is calculated by accumulating the sum of squares of gradient values of the objective function defied by residual of log wave field in the Laplace domain. The modeling parameter update unit updates a model parameter using the calculated scaled gradient direction value. The repetition control unit repeats processing until the completion condition is met by controlling the scaled gradient calculation unit and modeling parameter update unit. [Reference numerals] (100) Sound source estimation unit; (300) Wave form inverse operation unit; (310) Scaled gradient calculation unit; (330) Modeling parameter update unit; (350) Repetition control unit; (510) Measurement data processing unit; (530) Memory; (700) Imaging module; (AA) Measurement data