These data are also available within a separate WinZip archive (<https://pubs.usgs.gov/of/2010/1035/gis_catalog/bathymetry/svp/svp_csv.zip>).
Swath-bathymetric and acoustic-backscatter data were acquired with a SEA, Ltd., SWATHplus interferometric sonar operating at a 234-kHz frequency (<http://www.sea.co.uk/swathplus.aspx?nav=products>). The SWATHplus transducer was mounted at the bow of the USGS R/V Rafael. Bathymetric data were acquired over variable swath widths ranging from 10 to 100 m, in water depths of about 1 to 25 m. A total of 109 km of swath bathymetric data were collected.
SWATHplus acquisition software (version 3.05.90) was used to digitally log the bathymetric data at a rate of 30 pings/second and 3,072 samples per swath (ping) in the SWATHplus SXR format. Data collection parameters are saved into a SWATHplus session file in SEA's SXS format. These files that can be later used for data replay.
An Octopus F180R Attitude and Positioning system (see: <http://www.codaoctopus.com/motion/f180/index.asp>) recorded ship motion (heave, pitch, roll, and yaw). These data were transmitted via network connection to the SWATHplus data collection software. The Octopus F180R Inertial Measurement Unit (IMU) was mounted directly above the SWATHplus transducers, to minimize lever arm offsets that can lead to positioning errors. The F180R uses two L1 antennas for position and heading accuracy. The antennas are mounted on a rigid horizontal pole, 3 meters above the F180R IMU, with a horizontal separation of 1 meter and are offset from the IMU in a forward/aft configuration. The forward offset of the primary antenna from the IMU is 0.5 meters, with no port/starboard offset.
Eight sound-velocity profiles were acquired during survey operations at roughly 4-hr intervals using an Applied Microsystems SV Plus V2 Velocimeter (<http://www.appliedmicrosystems.com/products/productDetails.aspx?id=1>)
At each station, the SV plus 2 was hand deployed and slowly lowered to the seafloor. The SV plus v2 was monitored by a member of the science party and as the instrument made contact with the seafloor, the position (i.e. location) was recorded in the lab using HYPACK navigation software. The position was then manually recorded within the cruise log and SWATHplus acquisition software. Upon recovery, the SV plus was connected to an onboard computer via serial port in order to download data using the SV plus v2 communications software, SmartTalk.
Software: SV plus v2 SmartTalk (no version)
Software: Microsoft Excel 2004; Adobe Photoshop CS3 (10.0.1)
The following is a description of file contents:
Line 1: Sequential station number of the sound velocity profile (e.g. cast 1) Line 2: Description of the system used (e.g. SV plus) Line 3: Identification of the columns (Time (M/D/YYYY), Pressure (meters), Temperature (Celsius), Sound Velocity (meters/second), Battery (volts); Line 4: contains the units associated with line 3 (with the first column of information blank).
The remainder of the text file lists the actual sound velocity profile data. Example:
5/29/2008 1:01:21 PM,1443.60, -0.20, 13.428, 13.4
Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.