A description of the equipment, of the data acquisition and of the processing techniques used can be found hereafter. The cruise was based primarily on the TOBI side scan sonar surveying. The planning of survey lines was based on bathymetric maps created using all available data. Among these were data from Hydrographic Charts (digitized by the Defense Mapping Agency, USA), transits from the NGDC databases, transits from IFREMER cruises (courtesy of Dr. M. Cannat, cruise SUDACORES), and high resolution data from recent surveys (courtesy of the on-board Portuguese Team). GLORIA long-range sonar images originally published by R.Searle [1] were reprocessed at the SOC and were used for planning and navigation of TOBI as well.
Much of our initial efforts were aimed at processing of the navigation data since this would later be required for mosaicking of the sidescan sonar images and swath bathymetry. This led to the merging of all the available instrumental data (except the side-scan sonar data) into a single, self-consistent file. Additional data included the surface magnetometer and the TOBI ancillary data (three component magnetometer, temperature and conductivity data). This file is produced from an integrated procedure of filtering and merging of navigation and TOBI data, jointly with the offset data tables.