NAVIGATION AND DATA ACQUISITION

The vessel was set-up for multibeam data acquisition and navigation with PDS-2000 software by RESON. The UTC absolute time was measured and recorded at any shot produced by the PDS-2000 by the Java^TMDaphne software [Stanghellini and Bortoluzzi(2004)], interfaced to a Trimble Acutime and to the Fugro DGPS. The hull-mounted 16 transducer BENTHOS Chirp system was used. The data flow and performance were controlled by the Communication Technology's SWANPRO software. The SBP-CHIRP workstation received positions trough a sentence by the PDS-2000 and positions were therefore recorded on the XTF trace headers as lat/long of the DGPS antenna.

The instrumental offsets (PDS-2000) are presented in Fig. 8 and in Tab. 3

Table 3: Instrumental Offsets on Ship Urania (PDS2000). The GPS antenna (primary positioning system) is located on point DGPS.

POSITION	ACROSS	ALONG	HEIGHT
REFERENCE POINT	0.00	0.00	0.00
DGPS	1.64	14.30	14.18
MBEAM	0.00	14.36	-4.96
MAHRS	0.00	0.0	-3.40
ECHO SOUNDER 33	5.50	-1.85	-3.80
CHIRP	-1.0	11.80	-4.00
A-FRAME	6.5	-6.70	0.0
STERN	0.00	-30.60	0.00
STRING-1	4.00	-60.30	-60.0
STRING-2	-4.00	-60.30	-60.0
GI-GUN ARRAY	0.0	-60.3	-6.0

figure

Figure 8: Cruise STR06. Instrumental Offsets (PDS-2000) on R/V Urania