200 Hz Matched Field Processing on the September 1987 VLA Data Set
SCRIPPS INSTITUTION OF OCEANOGRAPHY LA JOLLA CA MARINE PHYSICAL LAB
Pagination or Media Count:
This technical report demonstrates, based on data collected at sea during the September 1987 Vertical Line Array VLA Experiment in the North-East Pacific, that matched field processing is a viable processing technique at 200 Hz and on a 900 m long vertical line array. The sound speed information derived from the CTD and XBT data collected during the experiment allows a good acoustic modeling by the ATLAS normal mode model of the CW transmissions. Although mismatch still exists, matched field processing produces good estimates of the source ranges for both fixed station transmissions. Source depth estimation appears, in this data set, a more difficult problem. The VLA system has acoustic navigation capabilities which show that the array, generally, has a tilt on the order of 1 deg. This tilt corresponds to a 15 m horizontal displacement from the top to the bottom of the array or two wavelengths at 200 Hz. Simulations indicate that array tilt can result in large losses and significant pattern changes in the range-depth ambiguity surfaces and is the main source of mismatch.
- Acoustic Detection and Detectors