NAVIGATION

The ship's NAVPRO 5.4 Navigation Software by Communication Technology was used. The primary positioning sensor was the FUGRO DGPS Mod. 3000 SeaStar. The system was used for ship's guidance on the planned lines and targets, and for data logging of various sensors, among them gyrocompass, Atlas DESO 25 echo/sounder, meteo. In addition, it routed positioning data to the NAVMAP and SBP Computers. The system performed quite well. The availability of Differential GPS signals by the FUGRO 3000 receiver was good, thus allowing metric accuracy for most of the acquisition time.

The Navigation System had the following major settings: time zone GMT, Datum WGS84, Projection Direct Mercator on 37 N (for navigation), Output position POS1.

Table 1: Offsets from primary navigation sensor (POS1). DEPTH1, DEPTH2 are Deso25 12/100 and 33/210 Khz.

COORDINATES
POINT	ALONG (Y)	ACROSS (X)
POS1	0.0	0.0
GYRO	-2.0	-2.0
DEPTH 1	1.5	-3.85
DEPTH 2	1.5	-0.15
CHIRP SBP	-11.0	-3.95
CORER	-18.5	5.0
STERN	-42.0	-2.0
MAG	-222.0	-10.0
GUN STBD	-52.0	2.5
ACTIVE STREAMER	-202.0	-2.0

Figure 3: Offsets from primary navigation sensor (POS1)