1pAO8. Heat flux monitoring in the Fram Strait: Limitations on travel-time measurements.

Session: Monday Afternoon, June 16


Author: Konstantin A. Naugolnykh
Location: CIRES, Univ. of Colorado/NOAA/Environ. Technol. Lab., 325 Broadway, Boulder, CO 80303
Author: Ola M. Johannessen
Location: Nansen Environ. and Remote Sensing Center, Bergen, Norway
Author: Igor B. Esipov
Location: N. Andreev Acoust. Inst., Moscow 117036, Russia
Author: Oleg B. Ovchinnikov
Location: N. Andreev Acoust. Inst., Moscow 117036, Russia
Author: Dimirii E. Leikin
Location: N. Andreev Acoust. Inst., Moscow 117036, Russia
Author: Yrii I. Tuzhilkin
Location: N. Andreev Acoust. Inst., Moscow 117036, Russia

Abstract:

Travel-time measurements form the common basis for all inverse techniques in ocean acoustics. These techniques rely on the assumption that the received signal consists of a train of pulses identical to that produced by the source. However, when few modes survive long-distance propagation, the validity of the travel-time measurement can be compromised by diffraction effects. A primary goal of this paper is to evaluate the restrictions caused by strong mode coupling in irregular sound channels. The results of numerical simulations of pulse propagation through a range-dependent medium with a single sound channel will be presented. The time-domain patterns were obtained by Fourier synthesis based on coupled-mode calculations for various inhomogeneities using a 100-Hz frequency band acoustic signal. The effects of modal dispersion and mode coupling on the accuracy of the pulse-travel-time measurements will be discussed.


ASA 133rd meeting - Penn State, June 1997