The multibeam data were logged into data set Saipan and collected using SAIC ISS-2000 software in the Generic Sensor Format and processed using SABER editing software. Sound velocity corrections from a Seabird SBE19 CTD sensor and motion corrections from a POS-MV vertical reference were applied to the data in real time. Predicted tides were applied to the data in real time and observed tides from Guam tide gauge 1630000 with a time corrector of 18 minutes and a tide height multiplier of 0.94 were applied using SABER postprocessing software.
Horizontal accuracy is 20m (no differential GPS correctors applied), vertical accuracy is depth dependent (~1% of water depth), WGS84 datum. These data are not to be used for navigation. Depths mapped range from 10 - 300 m.
The AHI's equipment serial numbers, software versions and sensor configuration settings are as follows:
RESON 8101-ER multibeam echosounder DOC inventory #: CD0000537418 Transducer serial #: 201004 Firmware, dry: 8101-2.07-2D4D Firmware, wet: 8101-1.06-2F6B
R/V AHI POS/MV Model 320, version 3 DOC inventory #: CD0000476647 PCS serial #: 474 IMU serial #: 203 Controller software: v 22.214.171.124 PCS Firmware: 2.16
Seabird SBE19 CTD: Serial #: 3029
R/V AHI Lever Arm Distances and Alignment Offsets The R/V AHI Reference Point (RP) is defined to be the intersection of the vessel's centerline, the cabin deck and the bulkhead immediately aft of the transducer. This is marked by a punch in the deck weld at that location. Positive X means the point is forward of the RP, positive Y means the point is to starboard of the RP, positive Z means the point is below the RP. The loaded waterline is defined as the intersection of the vessel's performance wing with the hull at the transom.
Antenna Baseline Distance, m: 1.229 Transducer depth below waterline, m 0.62
RP to IMU 0.80 0.00 0.08 RP to Primary GPS Antenna -3.55 -0.61 -1.88 RP to Vessel 0.16 0.00 0.77 RP to Sensor 1(MB transducer) 0.16 0.00 0.77 RP to Sensor 2 0 0 0 RP to Aux. GPS Antenna 0 0 0 RP to Heave lever arm(deg) -0.67 0.00 0.00 IMU rotation Ref. Frame, deg 0 0 0 Sensor 1 rotation Ref. Frame, deg 0 0 0 Sensor 2 rotation Ref. Frame, deg 0 0 0
Roll offset: +0.5 deg Pitch offset: 0.0 deg Gyro offset: 0.0 deg
Resource Description: Reson 8101ER Multibeam Sonar Data from Cruise OES-03-07/AHI-03-07. Data Set Name: Saipan.
These data are also archived through NOAA's National Geophysical Data Center at <http://www.ngdc.noaa.gov/mgg/bathymetry/multibeam.html>
Data Format - Generic Sensor Format, as described in <http://www.ldeo.columbia.edu/res/pi/MB-System/formatdoc/gsf_spec.pdf>