CRED Preliminary hard and soft bottom seafloor substrate map derived from an unsupervised classification of gridded backscatter and bathymetry derivatives at the U.S. Territory of Guam.

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Metadata:


Identification_Information:
Citation:
Citation_Information:
Originator:
Pacific Islands Benthic Habitat Mapping Center (PIBHMC), Coral Reef Ecosystem Division (CRED), Pacific Islands Fisheries Science Center (PIFSC), National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration (NOAA)
Publication_Date: 20081010
Title:
CRED Preliminary hard and soft bottom seafloor substrate map derived from an unsupervised classification of gridded backscatter and bathymetry derivatives at the U.S. Territory of Guam.
Geospatial_Data_Presentation_Form: digital data
Online_Linkage: <http://www.soest.hawaii.edu/pibhmc/pibhmc_cnmi.htm>
Description:
Abstract:
Preliminary hard and soft seafloor substrate map derived from an unsupervised classification of multibeam backscatter and bathymety derivatives at the U.S. Territory of Guam. The dataset was derived using Reson 8101 backscatter data, bathymetric variance and bathymetric rugosity. The sonar frequency is 240 kHz for the Reson 8101 backscatter data, which were resampled to a 5 m grid cell size prior to the classification. Limited seafloor photographs for groundtruthing are available for Guam and therefore no supervised classification was performed and we are unable to visually or empirically evaluate the accuracy of the unsupervised classification seafloor substrate map. However, in locations such French Frigate Shoals, NWHI and Tutuila, American Samoa, where ground truth data are available, the unsupervised classification method is a robust predictor of substrate type in similar depth ranges and seafloor environments.
Purpose:
The hard and soft seafloor map is being used to improve sampling techniques for long-term ecosystem monitoring, to guide future ground-truthing operations and to identify coral-rich and species specific environments. This is a preliminary product and the methods used to generate the map are currently being evaluated for their accuracy.
Supplemental_Information:
Multibeam bathymetry and backscatter data were collected aboard the R/V AHI (Acoustic Habitat Investigator). See the metadata for that dataset served separately at www.soest.hawaii.edu/pibhmc. The batymetric rugosity dataset is also served separately at the same website. The bathymetric variance grids were generated for use in the classification process and are not served separately. See the process description portion of this document for additional information about how the variance and unsupervised layers were derived.
Time_Period_of_Content:
Time_Period_Information:
Range_of_Dates/Times:
Beginning_Date: 20030922
Ending_Date: 20070522
Currentness_Reference: ground condition
Status:
Progress: Complete
Maintenance_and_Update_Frequency: As needed
Spatial_Domain:
Bounding_Coordinates:
West_Bounding_Coordinate: 144.59
East_Bounding_Coordinate: 144.98
North_Bounding_Coordinate: 13.68
South_Bounding_Coordinate: 13.22
Keywords:
Theme:
Theme_Keyword_Thesaurus: CoRIS Theme Thesaurus
Theme_Keyword:
EARTH SCIENCE > Biosphere > Zoology > Corals > Reef Monitoring and Assessment > Mapping > geomorphology Mapping
Theme:
Theme_Keyword_Thesaurus: None
Theme_Keyword: Hard bottom
Theme_Keyword: Soft bottom
Theme_Keyword: Unsupervised Classification
Theme_Keyword: Acoustic Imagery
Theme_Keyword: Multibeam Backscatter
Theme_Keyword: Backscatter
Theme_Keyword: Bathymetry
Theme_Keyword: Multibeam sonar
Theme_Keyword: Substrate
Theme:
Theme_Keyword_Thesaurus: ISO 19115 Topic Category
Theme_Keyword: imageryBaseMapsEarthCover
Theme_Keyword: 010
Theme:
Theme_Keyword_Thesaurus: CoRIS Discovery Thesaurus
Theme_Keyword: Geographic Information > Habitats
Place:
Place_Keyword_Thesaurus: None
Place_Keyword: UTM Zone 55
Place_Keyword: Guam Island
Place_Keyword: U.S. Territory
Place_Keyword: United States of America
Place:
Place_Keyword_Thesaurus: CoRIS Place Thesaurus
Place_Keyword:
OCEAN BASIN > Pacific Ocean > Western Pacific Ocean > Guam > Guam (13N144E0000)
Place_Keyword:
COUNTRY/TERRITORY > United States of America > Guam > Guam (13N144E0000)
Place:
Place_Keyword_Thesaurus: CoRIS Region
Place_Keyword: Guam
Access_Constraints: None
Use_Constraints:
These data are not to be used for navigation purposes. Please acknowledge the NOAA Pacific Islands Fisheries Science Center (PIFSC) Coral Reef Ecosystem Division (CRED) and the Pacific Islands Benthic Habitat Mapping Center (PIBHMC), and the Joint Institute for Marine and Atmospheric Research (JIMAR) and School of Ocean and Earth Science and Technology (SOEST), University of Hawaii as the sources of this information.
Point_of_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization:
Pacific Islands Benthic Habitat Mapping Center (PIBHMC), Coral Reef Ecosystem Division (CRED), Pacific Islands Fisheries Science Center (PIFSC), National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration (NOAA)
Contact_Address:
Address_Type: mailing and physical address
Address: NOAA IRC
Address: NMFS/PIFSC/CRED
Address: 1845 WASP Blvd., Building 176
City: Honolulu
State_or_Province: HI
Postal_Code: 96818
Contact_Voice_Telephone: 808 725-5360
Contact_Facsimile_Telephone: 808 725-5429
Contact_Electronic_Mail_Address: nmfs.pic.credinfo@noaa.gov
Contact_Instructions: e-mail preferred
Browse_Graphic:
Browse_Graphic_File_Name:
<http://www.soest.hawaii.edu/pibhmc/CNMI_images/gua-unspv-hardsoft-5m_445.jpg>
Browse_Graphic_File_Description: Hard and Soft Seafloor Substrate
Browse_Graphic_File_Type: JPEG
Data_Set_Credit: PIBHMC, CRED, PIFSC, NOAA, and JIMAR
Security_Information:
Security_Classification_System: Not applicable
Security_Classification: Unclassified
Security_Handling_Description: Not applicable
Native_Data_Set_Environment:
GeoTIFF file created using ENVI 4.4 in a LINUX computing environment

Data_Quality_Information:
Attribute_Accuracy:
Attribute_Accuracy_Report:
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.
Logical_Consistency_Report:
These data are believed to be logically consistent though no tests were performed
Completeness_Report: Complete
Positional_Accuracy:
Horizontal_Positional_Accuracy:
Horizontal_Positional_Accuracy_Report:
Horizontal positioning system: GPS (SPS) Horizontal position accuracy: 25 meters
Vertical_Positional_Accuracy:
Vertical_Positional_Accuracy_Report:
1 m Range resolution of sonar ~1.25 cm Raw sounding resolution: Variable Vertical accuracy of gridded product: 1% of water depth
Lineage:
Process_Step:
Process_Description:
Processing steps used to generate the backscatter, bathymetry, and bathymetric rugosity grids used in the unsupervised classification process are described in their own metadata that can be found at www.soest.hawaii.edu/pibhmc. Backscatter data were resampled to 5 m grid cell size using the Raster Resample Tool in the ArcMap Version 9.2 Toolbox. Resampling of the backscatter was performed after charted data in the GeoTIFF format were mosaicked using the ArcMap Version 9.2 Toolbox Mosaic to New Raster function. Mosaics were created in the ESRI GRID format. Bathymetric variance was calculated from the 5 m bathymetry in a two-step process using ArcMap Version 9.2. The first step involved calculating the standard deviation of the bathymetry layer using the Neighborhood Statistic tool from the Spatial Analyst pull-down menu in ArcMap Version 9.2. Rectangular neighborhood settings were set to a height and width of 2 grid cells to create a small-scale variance layer. The standard deviation output was then squared using the ArcMap Raster Calculater tool. A large-scale variance layer was also generated using a rectangular neighborhood height and width of 5 grid cells. The fine-scale variance is useful for defining small features that may indicate the presence of sediment ripples or possible coral-rich areas whereas the large-scale variance is useful for defining seafloor ridges, pinnacles, and significant changes in slope. Bathymetric variance proved to be a useful tool in previous efforts to map seafloor habitats by Dartnell and Gardner (2004). Their publication can be downloaded from www.soest.hawaii.edu/pibhmc/pibhmc_documentation.htm. Bathymetric rugosity was calculated using the ArcGIS Benthic Terrain Modeler (D.J. Wright et al., 2005) that is accessible for download at <http://www.csc.noaa.gov/products/btm>. The layers were then opened as ESRI GRIDS in the image processing software package ENVI (Environment for Visualizing Images) Version 4.4. A multi-band image was then created with the backscatter, small- and large-scale variance, and rugosity. A mask was also created in ENVI. Image classification was performed using the K-Means unsupervised classification method, which calculates initial class means evenly distributed in the data space and then iteratively clusters the pixels into the nearest class using a minimum distance technique. More information about K-Means algorithm can be found in the ENVI documentation available at www.ittvis.com/envi/. The number of classes was set to two and all other options were set to default. Class color mapping was performed on the resulting classified images. The substrate types of hard and soft were assigned based on results from supervised classification of the backscatter data (also performed in ENVI) using hard and soft bottom classes from classified seafloor photographs in other study sites including French Frigate Shoals, Northwestern Hawaiian Islands and Tutuila, American Samoa. Those datasets can be found at the PIBHMC website. In addition to the processing steps mentioned above, the high-intensity, track parallel, nadir signal was removed from the Reson 8101 backscatter after classification because it causes false classification results. The nadir signal was removed by creating a 15 m buffer in ArcGIS around the R/V AHI trackline navigation data sampled every second. The buffer was used to mask the Reson 8101 backscatter data and results in the trackline parallel unclassified data gaps. Methods to most accurately interpolate across the gaps are currently under investigation.
Process_Date: 2008

Spatial_Data_Organization_Information:
Direct_Spatial_Reference_Method: Raster
Raster_Object_Information:
Raster_Object_Type: Grid Cell
Row_Count: 7836
Column_Count: 9797
Vertical_Count: 1

Spatial_Reference_Information:
Horizontal_Coordinate_System_Definition:
Planar:
Grid_Coordinate_System:
Grid_Coordinate_System_Name: Universal Transverse Mercator
Universal_Transverse_Mercator:
UTM_Zone_Number: 55
Transverse_Mercator:
Scale_Factor_at_Central_Meridian: 0.9996
Longitude_of_Central_Meridian: 147
Latitude_of_Projection_Origin: 0
False_Easting: 500000
False_Northing: 0
Planar_Coordinate_Information:
Planar_Coordinate_Encoding_Method: Row and Column
Coordinate_Representation:
Abscissa_Resolution: 5
Ordinate_Resolution: 5
Planar_Distance_Units: meters
Geodetic_Model:
Horizontal_Datum_Name: D_WGS_1984
Ellipsoid_Name: WGS_1984
Semi-major_Axis: 6378137.000000
Denominator_of_Flattening_Ratio: 298.257224
Vertical_Coordinate_System_Definition:
Depth_System_Definition:
Depth_Datum_Name: mean lower low water
Depth_Resolution: 0.01
Depth_Distance_Units: meters
Depth_Encoding_Method: Attribute Values

Entity_and_Attribute_Information:
Overview_Description:
Entity_and_Attribute_Overview: none
Entity_and_Attribute_Detail_Citation: none

Distribution_Information:
Distributor:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization:
Pacific Islands Benthic Habitat Mapping Center (PIBHMC), Coral Reef Ecosystem Division (CRED), Pacific Islands Fisheries Science Center (PIFSC), National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration (NOAA)
Contact_Address:
Address_Type: mailing and physical address
Address: NOAA IRC
Address: NMFS/PIFSC/CRED
Address: 1845 WASP Blvd., Building 176
City: Honolulu
State_or_Province: HI
Postal_Code: 96818
Contact_Voice_Telephone: 808 725-5360
Contact_Facsimile_Telephone: 808 725-5429
Contact_Electronic_Mail_Address: nmfs.pic.credinfo@noaa.gov
Contact_Instructions: e-mail preferred
Resource_Description: Downloadable Data
Distribution_Liability:
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.
Standard_Order_Process:
Digital_Form:
Digital_Transfer_Information:
Format_Name: GeoTIFF, .tif
Format_Information_Content:
TIFF is a format for storage, transfer, display, and printing of raster images. The TIFF file structure allows both the tag and the image data to be encoded into the same file. GeoTIFF refers to a TIFF file that has geographic data embedded as tags within the TIFF file. The geographic data can be used to position the image in the correct location and geometry on the screen of a geographic information display. Any GIS, CAD, Image Processing, Desktop Mapping and other types of systems using geographic images can read any GeoTiff file. More specifically, files of this type can be added to ArcInfo and ArcView 8.x or higher and may be viewed in the Table of Contents as a new raster layer. Image visualization software that does not use geography as a basis for image placement can view a GeoTIFF image as if there were no geographic information in the TIFF file. For example, GeoTIFF files can be viewed using Windows Picture and Fax viewer. The GeoTIFF format is public domain, non-proprietary.
File_Decompression_Technique: none
Digital_Transfer_Option:
Online_Option:
Computer_Contact_Information:
Network_Address:
Network_Resource_Name: <http://www.soest.hawaii.edu/pibhmc/pibhmc_cnmi_gua_geomorph.htm>
Fees: None

Metadata_Reference_Information:
Metadata_Date: 20140312
Metadata_Review_Date: 20090508
Metadata_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization:
Pacific Islands Benthic Habitat Mapping Center (PIBHMC), Coral Reef Ecosystem Division (CRED), Pacific Islands Fisheries Science Center (PIFSC), National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration (NOAA)
Contact_Address:
Address_Type: mailing and physical address
Address: NOAA IRC
Address: NMFS/PIFSC/CRED
Address: 1845 WASP Blvd., Building 176
City: Honolulu
State_or_Province: HI
Postal_Code: 96818
Contact_Voice_Telephone: 808 725-5360
Contact_Facsimile_Telephone: 808 725-5429
Contact_Electronic_Mail_Address: nmfs.pic.credinfo@noaa.gov
Contact_Instructions: e-mail preferred
Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata
Metadata_Standard_Version: FGDC-STD-001-1998
Metadata_Time_Convention: Universal Time
Metadata_Access_Constraints: None
Metadata_Use_Constraints: None

CoRIS:
CoRIS_ID: 20090508045948
CoRIS_Children: None
CoRIS_Beginning_Date: 20030922
CoRIS_Ending_Date: 20070522
CoRIS_Metadata_Link:
<http://www.coris.noaa.gov/metadata/records/html/cred_guam_unspv_hardsoft_5m.html>
CoRIS_Tracking_ID: 2700

Generated by mp version 2.9.13 on Thu Jul 24 10:40:56 2014