CRED 20m Gridded bathymetry of Necker Island, Hawaii, USA (Arc ASCII format)

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: 20070301
Title:

CRED 20m Gridded bathymetry of Necker Island, Hawaii, USA (Arc ASCII format)

Geospatial_Data_Presentation_Form: digital data
Online_Linkage:

https://www.soest.hawaii.edu/pibhmc/cms/data-by-location/northwest-hawaiian-islands/

Description:

Abstract:

Gridded bathymetry of the shelf and slope environments of Necker Island, Northwestern Hawaiian Islands, Hawaii, USA. This ASCII includes multibeam bathymetry from the Simrad EM1002 and Simrad EM120 multibeam sonars collected as of October 2006 by the NOAA Coral Reef Ecosystem Division in depths between 20 and 1500 meters. The ASCII grid also includes estimated depths derived from high resolution IKONOS satellite imagery by the NOAA/NOS/NCCOS/CCMA Remote Sensing Team in shallow water between 0 and 16 meters.

Purpose:

The ASCII was created using data gathered from multibeam soundings and IKONOS estimated depths 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.

Supplemental_Information:

Data were collected aboard the R/V Kilo Moana, a 186' United States Navy owned research vessel. The R/V Kilo Moana's survey sensors include a 12 kHz Simrad EM120 sonar and a 95 kHz Simrad EM1002 sonar, which provide bathymetry and imagery data, a TSS/Applanix POS/MV Model 320, which measures position, velocity, attitude and heading, and a Sippican MK-21/PC based XBT system plus a Seabird SBE 9/11 CTD both of which measured sound velocity profiles.

IKONOS estimated depths were produced using rule-based, semi-automated image analysis of high-resolution satellite imagery for nine locations in the Northwestern Hawaiian Islands. For more information about the estimated depth data see the following online link: http://mercury.ornl.gov/metadata/nbii/html/nos/est%5Fdepth%5Fnwhi.html

Specific equipment configurations are documented in metadata from IKONOS Estimated Depths and cruises KM0206. These metadata can be accessed at: https://www.soest.hawaii.edu/pibhmc/cms/cruise-catalog/

Time_Period_of_Content:

Time_Period_Information:

Range_of_Dates/Times:

Beginning_Date: 2000
Ending_Date: 20021115

Currentness_Reference: ground condition

Status:

Progress: Complete
Maintenance_and_Update_Frequency: As needed

Spatial_Domain:

Bounding_Coordinates:

West_Bounding_Coordinate: -165.083508
East_Bounding_Coordinate: -164.070204
North_Bounding_Coordinate: 23.919511
South_Bounding_Coordinate: 23.114007

Keywords:

Theme:

Theme_Keyword_Thesaurus: NCEI Geoportal Filter
Theme_Keyword: CoRIS_Metadata

Theme:

Theme_Keyword_Thesaurus: CRCP Project
Theme_Keyword:

Benthic Habitat Mapping and Characterization - Northwestern and Main Hawaiian Islands

Theme_Keyword: 1217

Theme:

Theme_Keyword_Thesaurus: CoRIS Discovery Thesaurus
Theme_Keyword: Geographic Information > Bathymetry

Theme:

Theme_Keyword_Thesaurus: ISO 19115 Topic Category
Theme_Keyword: elevation
Theme_Keyword: 006

Theme:

Theme_Keyword_Thesaurus: CoRIS Theme Thesaurus
Theme_Keyword:

EARTH SCIENCE > Oceans > Bathymetry/Seafloor Topography > Bathymetry

Theme:

Theme_Keyword_Thesaurus: None
Theme_Keyword: Bathymetry
Theme_Keyword: Multibeam sonar
Theme_Keyword: satellite imagery
Theme_Keyword: estimated depth

Place:

Place_Keyword_Thesaurus: None
Place_Keyword: Necker Island
Place_Keyword: Hawaii
Place_Keyword: Northwestern Hawaiian Islands
Place_Keyword: United States of America

Place:

Place_Keyword_Thesaurus: CoRIS Place Thesaurus
Place_Keyword:

OCEAN BASIN > Pacific Ocean > Central Pacific Ocean > Northwestern Hawaiian Islands > Necker Island (23N164W0001)

Place_Keyword:

COUNTRY/TERRITORY > United States of America > Hawaii > Honolulu > Necker Island (23N164W0001)

Place:

Place_Keyword_Thesaurus: CoRIS Region
Place_Keyword: NWHI

Access_Constraints: None
Use_Constraints:

These data are not to be used for navigation purposes. Please acknowledge NOAA and the Joint Institute for Marine and Atmospheric Research, University of Hawaii as the sources of this information.

Point_of_Contact:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization:

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:

https://www.soest.hawaii.edu/pibhmc/NWHI_images/Necker_20m_500.jpg

Browse_Graphic_File_Description: Multibeam Bathymetry
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:

Native_Data_Set_Environment: ArcGIS ASCII file created in a LINUX 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 m

Vertical_Positional_Accuracy:

Vertical_Positional_Accuracy_Report:

1 m Raw sounding resolution: Variable

Lineage:

Process_Step:

Process_Description:

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 Pure File Magic (PFM) format in SABER and area based editing is performed. The edited PFM is then exported as X,Y,Z points with a defined grid cell size and the points are combined with X,Y,Z IKONOS estimated depth points. The resulting X,Y,Z data are then gridded using xyz2grd, a Generic Mapping Tools (GMT) algorithm that converts an ASCII or binary table to a netCDF grid file format. GMT is an open source collection of tools for manipulating geographic data sets. Grid nodes with more than one value are set to the average value and unconstrained nodes are set to NaN. Finally, the netCDF grid is clipped at a depth that minimizes data gaps for the specified grid cell size and then converted to an ArcGIS ASCII file format using LINUX/UNIX commands in combination with GMT. Additional information about GMT can be found at: www.soest.hawaii.edu/gmt and additional information about the multibeam data processing is recorded in the cruise metadata.

Process_Date: 20070122

Spatial_Data_Organization_Information:

Direct_Spatial_Reference_Method: Raster
Raster_Object_Information:

Raster_Object_Type: Grid Cell
Row_Count: 4432
Column_Count: 5143
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: 3
Transverse_Mercator:

Scale_Factor_at_Central_Meridian: 0.9996
Longitude_of_Central_Meridian: -165
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: 20
Ordinate_Resolution: 20

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:

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 1 meter.

Entity_and_Attribute_Detail_Citation: none

Distribution_Information:

Distributor:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization:

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: Arc ASCII, .asc
Format_Information_Content:

Arc ASCII can be converted to Arc Raster using ArcToolbox Conversion Tools.

Digital_Transfer_Option:

Online_Option:

Computer_Contact_Information:

Network_Address:

Network_Resource_Name:

ftp://ftp.soest.hawaii.edu/pibhmc/website/data/nwhi/bathymetry/Necker_20m.asc.zip

Fees: None

CRED 20m Gridded bathymetry of Necker Island, Hawaii, USA (Arc ASCII format)

Metadata: