Refraction_microtremor
Refraction microtremor (ReMi) is a surface-performed geophysical survey developed by Dr. John Louie (and others) based on previously existing principles of evaluating surface waves and in particular Rayleigh waves. The refraction microtremor technology was developed at the University of Nevada and is owned by the State of Nevada. Optim of Reno, Nevada has the exclusive license to develop the technology, and SeisOpt® ReMi™ has been available commercially from Optim since 2004. Since Rayleigh waves are dispersive, the propagating waves are measured along a linear seismic array and evaluated relative to wave frequency and slowness (or the inverse of the velocity). Due to the dispersive characteristics of higher frequency waves travelling through the more shallow conditions and lower frequency waves passing through deeper materials, a 1-D subsurface profile can be generated based on the velocity with depth.