title: Information and linearity of time-domain complex demodulated amplitude and phase data in shallow water.
abstract: Wave-theoretic ocean acoustic propagation modeling is used to derive the sensitivity of pressure, and complex demodulated amplitude and phase, at a receiver to the sound speed of the medium using the Born-Fréchet derivative. Although the procedure can be applied for pressure as a function of frequency instead of time, the time domain has advantages in practical problems, as linearity and signal-to-noise are more easily assigned in the time domain. The linearity and information content of these sensitivity kernels is explored for an example of a 3-4 kHz broadband pulse transmission in a 1 km shallow water Pekeris waveguide. Full-wave observations (pressure as a function of time) are seen to be too nonlinear for use in most practical cases, whereas envelope and phase data have a wider range of validity and provide complementary information. These results are used in simulated inversions with a more realistic sound speed profile, comparing the performance of amplitude and phase observations.
authors: Scripps Institution of Oceanography, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093-0238, USA. bsarkar@ucsd.edu
authors: Jit
authors: J
authors: Sarkar
authors: Bruce D
authors: BD
authors: Cornuelle
authors: W A
authors: WA
authors: Kuperman
mesh_terms: D000162:Acoustics; D003198:Computer Simulation; D016014:Linear Models; D009038:Motion; D009716:Numerical Analysis, Computer-Assisted; D009792:Oceans and Seas; D011312:Pressure; D012815:Signal Processing, Computer-Assisted; D013016:Sound; D013018:Sound Spectrography; D013997:Time Factors; D014867:Water
chemical_list: D014867:Water