The method is built up on registering the seismical waves that refract from the geological layers that attributed with different velocities.  A prerequisite of the application of the method is that the seismic velocities increases as the depth increases. 

The seismic velocity in a vertical section normally increases towards the depth as the composition and consolidation of materials give higher velocities.

On land, we use geophones and 24 channel digital seismographs. The usual geophone distance is 5 meter in refraction seismic surveys that set up in a 115 meter profile. With our roll along method we are able to create multiple lines connected together by overlapping geophones. This technique enables us to cover huge areas in a time and budget effect way.

As greater sediment thickness requires longer profiles, 10 or even 20 meter geophone distance can be applicable . The shot points are usually five times of the geophone distances, that gives usually 5 in-line shots and 2 off-end shots in a 115 meter profile. This setup is required to create a bedrock curve that covers the whole length of the profile.