To get a good result of the underground structures by using a fine-seismic-process the following is important: 1. Underground objects larger then 2m have to be seized. Therefore frequency range up to 500Hz one used and the one lower than 100 Hz are neglected. 2. A division of reflected waves from surface waves must be possible. That means surface waves need to flat away before the reflection waves reach the instrument. Or they have to reach the instruments later then the surface waves. That is technical not possible. Or they have to be taped separately for the plotting. 3. Disturbance by ground unrest and noise have to be reduced towards zero or at least by identification as what they are. Therefore only a sonic-altimeter-process is useful according to seismic reflection method witch reach reflected waves during the phase response. The GeoSONAR-method helps to minimize the field work activity by optimized results. The GeoSONAR-method needs a high frequented impulse, who is produce of a small electric-hammer, which has to be in control and reproducible. Therefore the impulse has to be a weak one. The single seat impulse in homogeneous underground proofs the structure of materials to a depth of 130m. In the in-situ the depths for useable results in about 80m.
The GeoSONAR-method is a process working on the base of reflections. Every measurement-point is penetrated by a lot of high frequented single impacts. The low energy is compensated by the high number of impacts and small stationary intervals. That is why the production of deep frequented high energy impacts is not necessary. By physical reasons only a high frequency response allows adequate resolutions of structures. The GeoSONAR-method produces the needed high frequencies and is able to proof underground cavity, cataracts etc..
To end the difficulties cursing the refinery underground it is necessary to get a much information as possible about the cavity system of the karst. To get this information the GeoSONAR-method can convince useful results and is a real bargain.