INTIFANTE'00 sea trial: data reports - Events I, II and III.

S.M. Jesus,
A.J. Silva,
C. Soares,
SiPLAB - FCT, University of Algarve
Campus de Gambelas,
PT-8000 Faro, Portugal

Comments: download file (pdf )
Ref.: SiPLAB Report 02/01, FCT, University of Algarve,2001.

The INTIFANTE'00 (INTIFANTE is a madeup acronym from INTImate and inFANTE) sea trial was carried out in the vicinity of Setúbal, situated approximately 50 km to the south of Lisbon, in Portugal, during the period from 9 to 29 October, 2000. The leading institutions were the Instituto Hidrográfico, that carried out the oceanographic observations and managed the research vessel NRP D. Carlos I, CINTAL/UALG that provided the acoustic data acquisition system and the emitted source signal control and IST, that was in charge of the high frequency data communications testing. Other collaborating/participating institutions were the NATO SACLANT Undersea Research Centre with the loan of the acoustic sound source and respective power amplifier and the Ente Nazionale per l'Energia ed l'Ambiente (ENEA) that participated in the hydrological survey.

This sea trial served a number of specific purposes under the leading projects INTIMATE and INFANTE, namely to acquire data for testing the Time-Reversal Mirror (TRM) for underwater communications at low-frequency (Event 1), internal tide acoustic tomography through a 25 hours observation of continuous transmissions (Event 2), source localization and tracking over strong environmental variability, (Event 3) and over a mild range dependent environment (Event 4). The data sets acquired during Events 1 to 3 are described in this report while Event 4 is described in a companion report. The experiment area was a rectangular box situated in the border of the continental platform with depths varying from 60 to 140 m and including a sharp submarine canyon (the Setúbal canyon) with depths rapidly reaching over 500 m. As an overview of the technical aspects involved in the experiment, it can be referred that acoustic signals were transmitted with an acoustic projector from onboard NRP D. Carlos I and received on a moored 16 hydrophone-4m spacing Vertical Line Array (VLA). The acoustic aperture of the vertical array was located between 30 and 90 m in a 120 m water column. The acoustic signals received in the VLA were transmitted via an RF link to the research ship NRP D. Carlos I, processed, monitored and stored. Various signals were emitted by the sound projector ranging from linear frequency modulated (LFM) sweeps, to broadband MPSK modulated binary sequences .