| 摘要 |
PROBLEM TO BE SOLVED: To provide an improved technique for evaluating a measurement value of a shear wave measured by using an ultrasonic wave.SOLUTION: A speed evaluation part specifies a measurement value satisfying a rejection condition from among the plurality of measurement values. A propagation speed Vs having a minus (inverse direction) code is an object of rejection under a condition 1. A propagation speed Vs outside a threshold range is an object of rejection under a condition 2. A propagation speed Vs at each depth in which a fluctuation is detected is an object of rejection under a condition 3. In a region (depth) in which a fluctuation occurs, it is difficult to specify a change in a phase displacement following passage of a shear wave, and it is difficult to measure a propagation speed Vs of a shear wave. Even if a propagation speed Vs of a shear wave can be measured in a region (depth) in which a fluctuation occurs, reliability of the measurement result is doubtful, and the propagation speed Vs at each depth in which a fluctuation is detected is an object of rejection since it is the result with low reliability.SELECTED DRAWING: Figure 7 |
