Coherent Acoustic Communications During the Littoral Warfare Advanced Development 99-1 Experiment
Abstract
Coherent acoustic communication experiments were performed during the Littoral Warfare Advanced Development exercise in the Gulf of Mexico in February 1999 (LWAD 99-1). The Acoustic Communication (ACOMM) experiment was allotted four segments of 5 hours each and two segments of one hour each. The ACOMM waveforms were projected using two mid-frequency acoustic sources (F-80 and F-56) and received at multiple platforms using vertical line arrays (VLA), sonobuoys (SSQ-57A), a submerged acoustic receiver, and TAN/SQS-53C sonar system. The ACOMM modems were aboard the Sea Diver platform; both modems were in the receiving mode. The received signals were processed in situ and stored on DAT tapes and 8-mm TEAC tapes for post experimental analysis. The analysis of the LWAD 99-1 experiment data shows strong multipath acoustic propagation environment, the first arrival weaker than later arrivals, and low signal-to-noise ratio (SNR). The reception at the deep VLA's (Sea Diver and Edwin Link) was very weak (almost absent) throughout the experiment. Data analysis using single phone reception without diversity resulted in high bit error rate (BER). The BER was drastically reduced when 4-channel spatial diversity was implemented, provided that there was sufficient SNR (> 10 dB) and the Doppler shift estimate was accurate.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 22, 2000
- Accession Number
- ADA377920
Entities
People
- Azmi Al-kurd
- Jeffrey A. Schindall
Organizations
- United States Naval Research Laboratory