MATERIALS AND METHODS

The research cruise was carried out with the 61 meter R/V Urania owned and operated by SO.PRO.MAR. and on long-term lease to CNR. Ship is normally used for geological, geophysical and oceanographical work in the Mediterranean Sea and adjoining waters, including but not limited to, the Atlantic Ocean, the Red Sea, and the Black Sea.

**Figure 4:** R/V *Urania*.
$\includegraphics[width=\linewidth]{IMG/urania_sinistra.eps}$

R/V Urania is equipped with DGPS positioning system (satellite link by FUGRO), single-beam and multibeam bathymetry and integrated geophysical and oceanographical data acquisition systems, including ADCP, CHIRP SBP and other Sonar Equipment, other than water and sediment sampling. Additional equipment can be accommodated on the keel or towed, e.g. Side Scan Sonars.

NAVIGATION, CHIRP SBP, SWATH BATHYMETRY

The vessel was set-up for data acquisition and navigation with PDS-2000 software by RESON, interfacing by a multiserial and Ethernet link several instruments, among them the DGPS (Fugro), the Atlas-Krupp Deso-25 single-beam echosunder, the MAHRS MRU and the meteorological station. The position and depth data were also distributed to the CTD data acquisition console. A Kongsberg processor running the SIS software, collected the multibeam data, including a SEAPATH MRU, compass, and DGPS. The MBES was the 70kHz, 400 1x2°, 150°aperture EM-710 (2000 m range) model by Kongsberg. The sonar head is positioned on the ship's keel using a V-shaped steel frame. A Sound Velocity probe at the keel 1m above the Sonar Head is interfaced directly to the MBES processor, thus providing the necessary real-time data for the beam-forming. CTD casts were normally used for input of the sound velocity profile to the system. An Anderaa Meteorological Station was also made available, at a rate of one measurement every 5 minutes, with (data sent in real time to an ISMAR's server

Table 1: Instrumental Offsets of PDS2000 on Ship Urania (PDS2000). The GPS antenna (primary positioning system) is located on point DGPS.

POSITION	ACROSS	ALONG	HEIGHT
REF.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
DESO	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
MAGNETOM.	-5.50	-210	0.0
DGPSGRAV	0.0	-4.0	10.0
GRAV	-1.0	-1.0	0.0

Table 2: Instrumental Offsets on Ship Urania (EM710). The DGPS antenna (primary positioning system) is located on point SEAPATH_GPS.

POSITION	ACROSS	ALONG	HEIGHT
REF. POINT	0.00	0.00	0.00
SEAPATH_GPS	-4.039	0.163	-18.211
MRU	-0.341	-1.342	-1.596
MBEAM_TX	0.0936	10.2964	5.0623
MBEAM_RX	-0.0031	11.0144	5.0600
SEALEVEL	0	0	-0.0875

MULTIBEAM BATHYMETRY

The SIS (EM-710) was able to build real-time DTM at the resolution of 20 and 5 m during the acquisition of the entire surveyed areas. The data from these production DTMs were exported and used for planning and update of the SIS projects. The raw data were instead saved in the Kongsberg's .all format, for postprocessing with packages like NEPTUNE or MB-SYSTEM or other. The processed data will therefore be used for an up-to-date regional and local bathymetric compilations.

CHIRP SBP

A Teledyne Benthos CHIRP SBP system (16 hull-mounted transducers) was used. The data were acquired by the SWANPRO software by Communication Technology, with direct interfacing to the DGPS, therefore actual positioning data have to be converted according to the offsets of Tab.1. The data were recorded in the XTF format and converted also into the SEG-Y format for processing with ISMAR's SEISPRHO package SEISPHRO.

Table 3: CTD Stations positions. Lat/lon data expressed as DDMM.xxxx. Time is UTC.

LON	LAT	STA	DATE TIME
1459.700	3832.517	01	06/02/2010 05.14.18
1504.836	3842.708	02	08/02/2010 08.39.02
1510.349	3854.976	03	09/02/2010 07.37.13
1421.908	3917.530	05	14/02/2010 13:41:14

Table 4: OBS launch positions. Lat/lon data expressed as DDMM.xxxx. Time is UTC.

LON LAT	UTM33	OBS	DATE TIME
1527.006 3840.008	539157 4279898	A4	2010-02-05T18.07.34
1420.089 3852.996	442306 4304032	A2	2010-02-06T00.36.41
1447.115 3901.971	481413 4320443	A5	2010-02-14T09.42.02
1423.601 3916.401	447672 4347287	A7	2010-02-14T14.33.46
1359.991 3929.997	414008 4372737	A6	2010-02-14T17.50.17

**Figure 5:** INGV OBS ready to launch. PANSTR10 .
$\includegraphics[width=\linewidth]{IMG/OBS_DROP_1.eps}$

MAGNETOMETRY, GRAVIMETRY

A Seaspy by Marine Magnetics magnetometer was used. Sensor was towed at 180 m from stern, on the port side. Data acquisition was by Marine Magnetic's Sealink software. During the acquisition a DTM of the anomaly data (IGRF 2010 model) has been continuously updated, and served well for planning purposes. A Lacoste S-54 Model ``Airsea System II'' gravimeter was used. System was installed near center of gravity of ship. In Messina an absolute measurement was performed at the dock.

OBS

Five OBS designed by INGV-CNT-OBS DANNA2007, DANNA2008, DALESSANDRO2009 were deployed (Figs. 5 and

). Table 4 shows the positions and date. Tables A5 and A6 in the Appendix show the instrumental characteristics and settings. Locations are in Fig. A2.

MAPPING AND MISCELLANEOUS

The datum was set to WGS84 and the UTM, zone 33N was chosen for navigation, display, and data acquisition. The time zone was set to the UTC for the instrumental data acquisition.