5-m grid of bathymetric data of Kohala coast of Hawaii, Main Hawaiian Islands, USA. The ASCII grids include multibeam bathymetry from the Reson 8101 multibeam sonar collected by the National Oceanic and Atmospheric Administration (NOAA) survey launch Acoustic Habitat Investigator (AHI) in 2012 of Kohala coast of Hawaii by the NOAA Coral Reef Ecosystem Division in depths between 0 And 157.4 meters. The 5-m grid also contains synthesis bathymetric data maintained by University of Hawaii at Manoa (UH) Hawaii Mapping Research Group (HMRG).
The ASCII grid was created using data gathered from multibeam depth measurements for use as a planning and reference document. The data are also being used for benthic habitat mapping, for locating Essential Fish Habitat, and for studying geologic features of the area. Refer to supplemental information for description of instrument and survey.
Multibeam data were collected aboard the R/V AHI (Acoustic Habitat Investigator), a 25' survey launch owned and operated by the NOAA Pacific Islands Fisheries Science Center in Honolulu, HI. The R/V AHI's survey sensors include a 240 kHz RESON 8101-ER sonar providing bathymetry and imagery data, a TSS/Applanix POS/MV Model 320 which measures position, velocity, attitude and heading, and a Seabird SBE 19 CTD used to measure sound velocity profiles. These metadata can be accessed at: http://www.soest.hawaii.edu/pibhmc/cms/cruise-catalog/ The synthesis gridded bathymetric data were maintained and metadata for these can be found at http://www.soest.hawaii.edu/HMRG/multibeam/index.php.
ground condition
These data are NOT TO BE USED FOR NAVIGATION purposes. Please acknowledge the PIFSC,the Joint Institute for Marine and Atmospheric Research(JIMAR), and CRED/PIBHMC as the sources of this information.
NOAA IRC
NMFS/PIFSC/CRED
1845 WASP Blvd., Building 176
e-mail preferred
http://www.soest.hawaii.edu/pibhmc/MHI_images/kohala_synth_5m_445.jpg
PIBHMC, CRED, PIFSC, NOAA, JIMAR, HMRG
Data are collected for resource management and research purposes and are tested for internal consistency; however, no effort is made to compare these data to external references or to other published data.
These data are believed to be logically consistent though no tests were performed.
Complete
Horizontal positioning system: GPS (SPS) Horizontal position accuracy: 25 m
1 m Raw sounding resolution: Variable
Multibeam swath files are acquired in the Generic Sensor Format (GSF) and are edited on a swath by swath basis using SAIC's SABER editing software. The edited swath files are then combined into a 5-m Pure File Magic (PFM) format in SABER and area based editing is performed. The edited PFM 5-m was then exported as X,Y,Z. The XYZ files were read into ArcGIS and combined with the 5-m synthesis data, and exported as an ArcASCII file.
Depth values are real values based on the average of the soundings that fell within the extracted grid cells. The number of soundings per grid cell range from >1000 soundings in shallow depths to as few as 20 soundings in deeper areas. A total error budget for this survey has not been developed. Therefore, the accuracy of depth measurements should be considered to be within 2 meters.
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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.
These data can be downloaded as either a 2-D binary netCDF raster grid or an ArcGIS ASCII text file. The netCDF grid is the default grid file format used by GMT (Generic Mapping Tools), which created this file. More information can be located at http://www.soest.hawaii.edu/gmt/and http://www.unidata.ucar.edu/software/netcdf/. The Arc ASCII file, for use in ESRI's (http://www.esri.com) GIS software, can be converted to an Arc Raster Grid using ArcToolbox ASCII to Raster conversion tool.
