PURPOSE: To enable the collection of vibration data maintaining simultaneity by a radio wave without restriction on the layout of sensors by recording data of vibration sensors simultaneously at local stations based on a control signal from a control station.
CONSTITUTION: Various control signal generators for starting, ending, updating time and the like are arranged at a control station 1. At local stations 2, a signal received 5 from the station 1 is converted to a monitoring signal and a trigger signal with a signal processing section 6 and outputted to a recorder 7 to start a recording by a starting order transmitted from the station 1 by the trigger signal checking the state of communication by the monitoring signal. When a measurement start order is emitted from the station 1, the stations 2 start a measurement of vibration of a subsoil simultaneously to collect vibration data with the recorder 7. Then, a phase velocity curve is determined by a frequency-wave number analysis from the data and compared with a theory curve of a phase velocity of a surface wave in an underground structure. Thus, S wave and P wave velocities can be determined at a certain depth thereby enabling analyzation of the underground structure.
KATAOKA SHUNICHI
SATO TOSHIAKI
KAWASE HIROSHI
