Travel times in complex environments
* Presenting author
Times of Arrival (TOAs) of propagated signals are of utmost interest in seismic, underwater as well as aerial acoustics. From TOAs, one may reconstruct the propagation media properties from known sources and sensors positions, or conversely, find sound events locations in a known environment. Modeling the TOAs in realistic environments (wind or current, sound speed gradients, obstacles…) requires a very general physical model, able to factor in the impact of refractive and diffractive processes. We present an interface-tracking model based on Sethian's Fast-Marching method for computing TOAs. This method is applicable to complex 3D meshed environments. Examples will be given in an urban area, in the complex atmosphere, as well as in the ocean. The combination of the marching model with the time-matching principle is illustrated to yield a general localization framework applicable to these various environments.