geophysical techniques remain the only ways to remotely and non-destructively sense the earth’s near subsurface and as such have the most promising prospect for rapid and accurate detection of underground tunnels. today, electrical resistivity and seismic refraction geophysical methods have been greatly developed to identify structures and underground cavities. in this study, the ability of the...

A B S T R A C T A new type of seismic imaging, based on Feynman path integrals for waveform modelling , is capable of producing accurate subsurface images without any need for a reference velocity model. Instead of the usual optimization for traveltime curves with maximal signal semblance, a weighted summation over all representative curves avoids the need for velocity analysis, with its common...

One way of developing a wave-equation approach to seismic imaging is based on the concept of downward continuation of the surface reflection data. Seismic imaging is typically based on the single scattering approximation, and assumes the knowledge of a, smooth, background model in which the mentioned downward continuation is carried out. The downward continued data are subjected, at each depth,...

development of ultrasound technique has not been progressing for evaluating the internal quality of fruits as fast as that of processed foods. in this research for quality assessment of pear fruit (shah miveh variety) an ultrasonic measurement system was constructed to transmit and receive the ultrasonic waves. the apparatus included a pulser-receiver, a pair of 75 khz ultrasonic transducers wi...

this paper is devoted to compiling a site geology map for town of amiriyeh, from seismic macro-zonation point of view using geophysical methods of shallow seismic, down-hole seismic and resistivity surveys. in this map site geology has been classified based on shear wave velocity, according to the criteria for site geology classification offered in the iranian code of practice for seismic resis...