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 was deployed from the NOAA Ship Oscar E. Sette and surveyed independently during ship operations in other locations in American Samoa.
The multibeam bathymetric data in generic sensor format from AHI0402 were submitted to NOAA's National Geophysical Data Center (NGDC) in Boulder, CO, for distribution in 2005.
Equipment serial numbers and software versions are as follows:
RESON 8101-ER multibeam echosounder DOC inventory #: CD0000537418 Firmware, dry: 8101-2.07-2D4D Firmware, wet: 8101-1.06-2F6B
POS/MV Model 320, version 3 DOC inventory #: CD0000476647 PCS serial #: 474 IMU serial #: 203 Controller software: v 1.0.5.0
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 AHI0402 (R/V AHI)
Online Links:
Benthic Habitat Mapping Group, Coral Reef Ecosystem Division (CRED), Pacific Islands Fisheries Science Center (PIFSC), NOAA
The data were collected in support of Coral Reef Conservation Program goals to map all shallow (0-30 m)coral reefs in US Pacific waters and priority moderate (> 30 m) depth areas by 2009. The data are being used to provide bathymetric and backscatter data for previously unmapped areas; in support of ecosystem management requirements for benthic habitat mapping and location of Essential Fish Habitat; and to study the geologic features of the area.
Are there legal restrictions on access or use of the data?
- Access_Constraints: None
- Use_Constraints:
- These data are NOT TO BE USED FOR NAVIGATION. Please acknowledge the NOAA Coral Reef Ecosystem Division, Pacific Islands Fisheries Science Center as the source of this information.
These data are not to be used for navigational purposes. NOAA makes no warranty regarding these data, expressed or implied, nor does the fact of distribution constitute such a warranty. NOAA cannot assume liability for any damages caused by any errors or omissions in these data, nor as a result of the failure of these data to function on a particular system.
Please contact the Distributor (see above) for distribution optionsThese 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