Re: Seismic refraction survey and seismic refraction tomogra
Lary,
Although most data acquisition equipment can be used for both methods, the models, data processing and field procedures are quite different.
Standard seismic refraction method assumes subhorizontal layered model. Within each layer, there are no seismic velocity variations in the vertical direction, although lateral variations are allowed. In seismic refraction tomography (SRT) the velocity can change gradually within each layer both vertically and horizontally, especially for the overburden soils on top of bedrocks. So the velocity model is more flexible.
The methods for interpretation are also different for both types of seismic surveys. Although the inversion process are different, they both need to pick the first arrivals of the traces. SRT involves more complex mathematical algorithms to fit more flexible models.
In the field procedure, SRT generally needs more shots than standard seismic refraction survey to obtain high resolution profiles. In this sense, marine seismic surveys are more cost effective for SRT than land surveys.
hope this helped!