Gridded multibeam bathymetry is integrated with bathymetry derived from multpectral World View-2 satellite data. Gridded (10 m cell size) multibeam bathymetry collected aboard NOAA Ship Hiialaka'i and R/V AHI in 2007, a 224 (68 m) United States National Oceanographic and Atmospheric Administration research ship. Bathymetry values shallower than ~20 m were derived by gauging the reletive attenuation of coastal, blue, green and yellow spectral radiance as a function of depth. A multiple linear regression analysis of coastal, blue, green and yellow band spectral values against depth determined the variables of y-intercept, coastal,blue, green and yellow slope values. Variables then used in multivariate slope intercept formula to derive depth. Digital image processing to derive depths conducted with the ENVI 4.8 software program while data editing and integration was performed using ArcGIS 10.1 This data set is for the shelf environment of Baker Island.
The data were derived in support of NOAA Coral Reef Conservation Program goals. Goal 1 is to map all U.S. Coral Reef Ecosystems. This data set specifically addresses Objective 1 and 4: to develop high-resolution benthic maps and to characterize priority deep water reefs and associated habitats. This integration of derived bathymetry with multibeam sonar data provides a GIS layer with expanded spatial coverage that may be used for benthic and essential fish habitat characterization, and for the study of geologic features. By combining the dataset with other bathymetry, backscatter, derivatives, and in situ data, they collectively compose benthic habitat maps designed to be used to understand and predict shallow depth (0m to 600m) benthic habitats for organisms that inhabit coral reef ecosystems.
Data were collected aboard the NOAA Ship Hiialakai, a 218' United States National Oceanographic and Atmospheric Administration research ship. The NOAA Ship Hiialakai's survey sensors include a 300 kHz Simrad EM300 sonar and a 3000 kHz Simrad EM3002D sonar, which provide bathymetry and imagery data, a TSS/Applanix POS/MV Model 320, which measures position, velocity, attitude and heading, and a Seabird SBE 9/11 plus CTD used to measure sound velocity profiles. Sensor configuration for the Hi'ialakai for cruise HI-06-01 is documented in the cruise/multibeam metadata file HI0601_MB_Metadata.txt. Data were also 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. Sensor configuration for the AHI for cruise AHI-06-01 is documented in the cruise/multibeam metadata file AHI0601_MB_Metadata.txt. Original World View-2 imagery was purchased to support the Pacific Islands Geographic Information System (GIS) project and National Ocean Service's (NOS) coral mapping activities. Orthographically corrected World View-2 Imagery was provided by NOAA. The metadata for this World View-2 imagery is documented in the original product metadata, 12NOV15222828-M2AS-052760757130_01_P001 (http://www.soest.hawaii.edu/pibhmc/).
ground condition
These data are not to be used for navigation purposes. Please acknowledge the NOAA Coral Reef Ecosystem Division, Pacific Islands Fisheries Science Center and the Pacific Islands Benthic Habitat Mapping Center, School of Ocean and Earth Science and Technology, University of Hawaii as the sources of this information.
NOAA IRC
NMFS/PIFSC/CRED
1845 WASP Blvd., Building 176
http://www.soest.hawaii.edu/pibhmc/PRIAs_images/BAK_DBMB_5m_445.jpg
Benthic Habitat Mapping Group, Coral Reef Ecosystem Division (CRED), Pacific Islands Fisheries Science Center (PIFSC), NOAA
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 C/A Horizontal position accuracy: 25 meters
Range resolution of sonar: varies with depth Raw sounding resolution: varies with depth Vertical accuracy of gridded sonar product: ~ 1% of water depth Vertical accuracy of derived bathymetry product: 2 meter range
Multiple tools in ENVI 4.8 were used to complete the following processing steps: Data conversion from digital number to radiance, correction for atmosphere and water surface reflection, masking of non-applicable values, and bathymetric derivation using variables from multiple linear regression analysis. Multiple tools in ArcGIS 10 were used for dataset integration and to extract values for the multiple linear regression analysis and subsequent error analyses. The Microsoft program Excel was used for the multiple linear regression analysis to provide original variables for depth derivation. The multivariate slope intercept formula used to derive depth was Depth=Yint+(Mcoastal)(Xcoastal)+(Mblue)(Xblue)+ (Mgreen)(Xgreen)+(Myellow)(XYellow). The product was derived, from the original image 12NOV15222828-M2AS-052760757130_01_P001,which was devided into "shallow" and "deep". The MLR variables for "shallow" were Yint=-11.56329496, Myellow=0.222613167, for "deep" were Yint=6.239651333, coastal=-0.084602686, Mblue=-0.927123325, Mgreen=1.724580484, Myellow=-0.608902229. The derived bathymetry were in turn mosaiced giving the data from "shallow" priority in depth >/= -6 and "deep" in depth <-6 due to its statistaclly higher accuracy. The final mosaic was resampled to a lower resolution of 5m. This derived bathymetry product (BAK_DBAll_5m) was then integrated with the multibeam sonar data, with sonar data prioritized over derived data, to create the final product (BAK_DBMB_5m). A detailed description of all processing steps and an error analysis of each derived bathymetry grid used is available upon request.
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.
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