Recently, structures of strata and permeability in the rock mass have been investigated with borehole radar systems using electromagnetic waves.
As a result of examinations, the explorative distance of the system was limited from 100 meters in the fractuered granite rock mass under present conditons in Japan, and further improvements are needed to lengthen its explorative distance.
Using the propagative characteristics of electromagnetic waves, high permeability zones (hydraulic pathways) can be estimated by the tomographic data obtained from the results of crosshole measurements before and after salt water injection.
