Notes for Geoacoustic_TDFD

Abstract

These notes were written to help users run the WHOI TDFD (Time Domain Finite Difference) elastic wave equation code that was prepared for distribution through the ONR Ocean Acoustics Library (http://www.hlsresearch.com/oalib/). The code and documentation are based on materials that were developed for a Numerical Wave Propagation class given at MIT in the Fall of 2000. The code used is the full two-dimensional time-domain finite-difference code developed at WHOI over the past 25 years, but in order to reduce the number of variables to a manageable size, we consider a two dimensional, isotropic problem with fixed parameters in time and space. For example, the source waveform in time for both beam and point sources is a RICKER wavelet, time units have been normalized to periods (defined at the peak frequency for pressure in water), space units have been normalized to water speed and density of 1! .5km/sec and 1000kg/m3) and the domain size has been fixed at 72 x 12 water wavelengths.