Accession Number:

ADA629858

Title:

Coherent Path Beamformer Front End for High Performance Acoustic Modems

Descriptive Note:

Corporate Author:

FLORIDA ATLANTIC UNIV BOCA RATON DEPT OF OCEAN ENGINEERING

Personal Author(s):

Report Date:

1999-09-30

Pagination or Media Count:

10.0

Abstract:

LONG-TERM GOALS. The long-term objective is a smart acoustic network for multiple Autonomous Underwater Vehicles AUV operation, with integrated communication and positioning capability. To do so, a new generation of Coherent Path Beamformer CPB will act as a network decoder and arbitrator for data communication and long short base line. Also, wireless communication to shore would be available for control and real-time data transfer. Finally, the AUV s will be carrying an improved version of the compact low-cost Acoustic Modem. This will require extensive research and testings of our adaptive beamformer front-end, now built and tested in the ocean. An adaptive coherent filtering process is being developed to decode information transmitted at high data rate exceeding 16kbps in very shallow water, suitable for transmission of image information from AUVs. As a second but equally important long term goal, based on experimental data, is to obtain a better understanding of environmental acoustics related to information transmission underwater. This knowledge will be used to develop a test model for evaluating under water acoustic modem and other shallow water sonar system performance. OBJECTIVES. Our Scientific objectives in this effort are to conduct at sea acoustic transmission experiments at frequencies from 16kHz to 32kHz, using a 32 by 32 Mills-Cross array and a single-channel acoustic modem. The intents are to measure and characterize the underwater acoustic channel, receive data collected by the AUV s, remotely control and monitor multiple AUV s during at sea operation. We are also using the experimental data to evaluate the performance of the Coherent Path Beamformer in very shallow water and highly reverberant environment. These results are also being used to develop a low-cost, high-reliability beamformer modemlong-base-line combination for use by the AUVs.

Subject Categories:

  • Acoustics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE