'CHIRP' SBP data were acquired by a 5x5 hull mounted Edgetech Mod.X-STAR FULL SPECTRUM Sonar profiler, with operating frequencies ranging between 2 and 5 kHz. The pulse length was maintained at 100 ms while the trigger rates varied from 0.1 to 0.2 Hz according to water depth. The signal penetration was up to 120-130 m below the sea floor. The sonar was controlled by the Edgetech's DISCOVER-SUB-BOTTOM V3.30 software. Digital data were recorded in the JSF format on hard disk. The proprietary format will be converted to SEG-Y for processing.
The navigation data was made available to the system at a rate of aproximately 1 Hz.