EM300 multibeam data were collected in
15 March to 8 April 2006 aboard NOAA Ship Hi'ialakai at
Jarvis Island, Palmyra Island, and Kingman Island in the
Central Pacific during cruise HI-06-04. These multibeam
data were collected using SAIC ISS-2000 software in the
Generic Sensor Format and processed using SABER editing
software. Surface sound velocity values were supplied by a
Seabird SBE-45 MicroTSG and a SBE-38 remote temperature
probe. Sound velocity corrections from a Seabird 911 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. At
Jarvis Island, Hilo (1617760) predicted tides were used
with a +2.0 time corrector and a range ratio of 1.10.
At Palmyra and Kingman, Honolulu (1612340) predicted tides
were used with a +1 hr 19 min time corrector and a range ratio
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 20 to 3500 m.
Concurrent mapping was done by the R/V AHI in water depths
ranging from 10-250 m with the data set being AHI-06-04;
metadata for AHI-06-04 are submitted separately.
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.
Data were collected aboard the NOAA Ship Hi'ialakai, a 68 m
(218') United States National Oceanographic and Atmospheric
Agency (NOAA) research ship. The NOAA Ship Hiialakai's
survey sensors include a 30 kHz Simrad EM300 sonar and a
300 kHz Simrad EM3002d sonar (not used on HI-06-04), both of
which measure bathymetry
and acoustic backscatter imagery, a TSS/Applanix POS/MV Model
320, which measures time, position, velocity, attitude and
heading, and a Seabird SBE 9/11 plus CTD used to measure
sound velocity profiles.
The Hi'ialakai's equipment serial numbers, software
versions and sensor configuration settings are as follows:
SIMRAD EM300 multibeam echosounder
Serial #: 303
PU Software Versions:
1.1.3 040427,2.0.0 040614,2.3.2 040615,2.0.1 040629
SIS Software Version: 1.0, build 117, July 2, 2004
HI'IALAKAI POS/MV Model 320, version 3
PCS serial #: 295
IMU serial #: 1333
PCS Firmware: 2.21, Feb 02, 2006
Controller software: v 2.1
Seabird SBE 9/11 plus CTD:
Serial #: 09P35130-0737
Hi'ialakai Lever Arm Distances and Alignment Offsets: The
Hi'ialakai's Reference Point (RP) is a granite block
situated 1.222 m starboard of the ship's centerline, 1.23 m
above the ship's baseline/datum on the keel. The RP is
located under the forward deck, in the ship's laundry room.
The ship's sensors, the sonar systems and permanent
benchmarks are measured with respect to the RP. 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 survey waterline is defined to be at
the 15' draft mark on the vessel's starboard side.
POS/MV Settings: X Y Z
RP to IMU, m 0.434 0.000 -0.117
RP to Primary GPS(port),m -18.101 -2.011 -23.545
RP to Vessel, m 0.00 0.00 0.00
IMU w.r.t. Ref. Frame, deg 0.00 0.00 0.00
RP to Heave lever arm, m -14.532 -1.179 -5.234
Sensor 1 & 2 lever arms & angles: 0 0 0
Antenna Baseline Distance: 1.779
EM300 Settings: X Y Z
Pos sensors 1 2 & 3, m 0 0 0
TX Transducer, m -04.091 -2.217 1.727
RX Transducer, m -06.065 -1.222 1.727
Attitude sensors 1 & 2, m 0 0 0
Waterline, m -3.26
Roll Pitch Heading
TX Transducer, deg 0.00 0.00 359.96
RX Transducer, deg 0.00 0.00 0.05
Attitude 1, deg -0.20 0.00 0.00
Attitude 2, deg 0 0 0
Stand-alone heading, deg 0
Resource Description: EM300 Multibeam Sonar Data
from Cruise Hi'ialakai HI-06-04
These data are NOT TO BE USED FOR NAVIGATION
1845 WASP Blvd., Building 176
Joyce E. Miller Coral Reef Ecosystem Division,
NOAA Pacific Islands Fisheries Science Center
Horizontal accuracy is ~20 m as data were collected using GPS with no differential corrections. Vertical accuracy of multibeam data is estimated at 1% of water depth. Predicted tides were applied to the data in real time. At Jarvis Island, Hilo (1617760) predicted tides were used with a +2.0 time corrector and a range ratio of 1.10. At Palmyra and Kingman, Honolulu (1612340) predicted tides were used with a +1 hr 19 min time corrector and a range ratio of 0.56.
These data are believed to be logically consistent though no tests were performed
Multibeam sonar data. No DGPS corrections applied; 20 m accuracy
Accuracy varies with water depth. Predicted tide correctors applied; multibeam data vertical accuracy is ~1% of water depth.
Simrad EM 300 (30 kHz) bathymetry and imagery data were collected in depths of ~100m-4000m. The EM 300 system was placed in stand-by mode in shallower water due to high noise levels.
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 options 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