Most shallow seismic refraction operations have not taken advantage of advances in technology for acquisition, processing or interpretation, they are under-capitalized and they are relatively inefficient. Where shallow refraction technology was once perceived to be twenty years behind reflection methods, the difference is now nearer half a century. See millennium.pdf for a vision of shallow seismic refraction methods which is more appropriate to the future.

 

Palmer, D, 2001. A new direction for shallow refraction seismology: integrating amplitudes and traveltimes with the refraction convolution section. Geophysical Prospecting 49, 657-673.

The refraction convolution section (RCS) is a new method for imaging shallow seismic refraction data. It is a simple and efficient approach to full trace processing which generates a time cross-section similar to the familiar reflection cross-section. The RCS advances the interpretation of shallow seismic refraction data through the inclusion of time structure and amplitudes within a single presentation.

 

 

Palmer, D, 2001. Imaging refractors with the convolution section. Geophysics 66, 1583-1589.
Palmer, D, 2001. Resolving refractor ambiguities with amplitudes. Geophysics 66, 1590-1593.

 

More useful geological interpretations are possible with simple 3D sets of data with complete spatial coverage in all directions, than with the most detailed inversion of 2D sets of data. See 3D.pdf and fabric.pdf for more details.

 

The RCS provides a fundamental change in approach to the processing of refraction data. Rather than firstly measuring traveltimes, then processing the data, the RCS permits processing first, stacking to enhance signal-to-noise ratios, then the measurement of travelimes. This approach, which has many interesting parallels with conventional CMP methods with reflection processing, may have significant benefits in the processing of second arrival data, especially with shear wave statics (see GRM & RCS Statics.pdf).

 

A comprehensive description of the RCS and its application to many problems, such as non-uniqueness (see Starting Models.pdf), improving spatial resolution, improving signal-to-noise ratios, second and later events, and amplitude 'statics' (see ampstatics.pdf) can be found in my Ph D thesis. Email d.palmer@unsw.edu.au with your request for a pdf version of this document.

 

Research Opportunities are available in the application of seismic reflection processing techniques to the RCS, quantitative measures of anisotropy with 3D methods for the determination of rock fabric and fracture porosity for geotechnical, groundwater and environmental applications, elastic properties with three component methods, refraction statics especially for S wave data, and innovative acquisition methods.