SOUND VELOCITY ANALYSIS

The Sound Velocity data were obtained by utilizing the data of the SBE probe during the downcasts on some of the scheduled CTD stations. A SVP sensor provided a continuous, direct estimate of the sound velocity at the sonar head, being interfaced to the 8160 SeaBat 81-P processor.

The position of the CTD stations are reported in Table 11.

Table 11: MFSTEP2 CTD/SVP Locations.

Longitude	Latitude	Station	UTC time	System Time	Depth
010:45.84	41:54.99		11:31:29	2005-Apr-13 13:29:27
010:25.44	42:21.56	A5	17:27:16	2005-Apr-13 19:25:16	443
010:03.67	42:48.16	a4	21:40:26	2005-Apr-13 23:38:27	91
010:26.28	43:01.91	100	23:57:09	2005-Apr-14 01:55:10	76
010:16.24	43:02.11	102	01:12:44	2005-Apr-14 03:10:46	120.8

The more interesting data are presented in Fig. 16. The SV profiles were used for real-time acquisition and post-processing, being input to the PDS-2000 software just after collection and conversion to ASCII (depth,svp, space delimited) by the SeaBird VMDAS software.

figure

Figure 16: Plot of Speed of sound of the CTD data used for Multibeam.