DISTRIBUTED SURVEY SYSTEM FOR OBTAINING UNDERGROUND ELECTRICAL CHARACTERISTICS AND DISTRIBUTED SURVEY METHOD USING SAME

A distributed survey system for obtaining underground electrical characteristics and a distributed survey method using said distributed survey system are provided, said distributed survey system being capable of flexibly accommodating different survey purposes, survey-region geographical conditions, and the like and thus being capable of obtaining underground electrical characteristics over a shorter time frame and more efficiently than existing technologies. In the present invention, a plurality of survey units (1, 2, 3, , (N-1), N) are distributed across a region in which underground electrical characteristics are to be obtained. Each of said survey units is provided with one or both of the following: one or more current-supply points (TX) and a current-supplying means for supplying current thereto underground; and/or one or more measurement points (RX) and a measuring means for measuring response signals from the measurement point(s) (RX) in response to the aforementioned current. A synchronization control means is provided in each survey unit. Said synchronization control means synchronize the operations of the current-supplying means and measuring means between survey units, supply currents from the plurality of current-supply points (TX) using waveforms encoded so as to yield a covariance of zero, and make the measuring means measure the response signals in response to said currents.