studying gaussian beam is a method to investigate laser beam propagation and abcd matrix is a fast and simple method to simulate gaussian beam propagation in different mediums. of the abcd matrices studied so far, reflection and refraction matrices at various surfaces have attracted a lot of researches. however in previous work the incident beam and the principle axis of surface are in parallel...

Compressional(Vp) and shear-wave (Vs) velocities were determined within earthen levees on the Rio Grande River in south Texas, south New Mexico and New Orleans. A loosely fitting relationship was developed to better characterize the internal condition of the levees. Seismic data were incorporated with surface observations, existing core taken from the levee, and airborne EM data acquired. Sever...

The inversion of seismic travel-time data for radially varying media was initially investigated by Herglotz, Wiechert, and Bateman (the HWB method) in the early part of the 20th century [1]. Tomographic inversions for laterally varying media began in seismology starting in the 1970's. This included early work by Aki, Christoffersson, and Husebye who developed an inversion technique for estimati...

We apply the P-wave refraction-tomography method to seismic data collected with a landstreamer. Refractiontomography inversion solutions were determined using regularization parameters that provided the most realistic near-surface solutions that best matched the dipping layer structure of nearby outcrops. A reasonably well matched solution was obtained using an unusual set of optimal regulariza...