CRED 20m Gridded bathymetry of Nihoa 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: 20070416
Title:

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

Geospatial_Data_Presentation_Form: digital data
Online_Linkage:

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

Description:

Abstract:

Gridded bathymetry (20m) of the shelf and slope environments of Nihoa Island, Hawaii, USA. The ASCII includes multibeam bathymetry from the Simrad EM120, Simrad EM1002 Simrad EM300, Simrad EM3002d multibeam sonars collected as of October 2006 by the NOAA Coral Reef Ecosystem Division in depths between 20 and 1000 meters.

Purpose:

The ASCII was created using data gathered from multibeam soundings 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:

Multibeam data were collected aboard the NOAA Ship Hi'ialakai, a 218' United States National Oceanographic and Atmospheric Administration research ship. The NOAA Ship Hiialakai's survey sensors include a 30 kHz Simrad EM300 sonar and a 300 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.

Specific equipment configurations are documented in cruise metadata from the following cruises: KM0206, HI0501, HI0612. These metadata can be accessed at: http://www.soest.hawaii.edu/pibhmc/cms/cruise-catalog/

Time_Period_of_Content:

Time_Period_Information:

Range_of_Dates/Times:

Beginning_Date: 20021022
Ending_Date: 20061029

Currentness_Reference: ground condition

Status:

Progress: Complete
Maintenance_and_Update_Frequency: As needed

Spatial_Domain:

Bounding_Coordinates:

West_Bounding_Coordinate: -162.501792
East_Bounding_Coordinate: -161.554103
North_Bounding_Coordinate: 23.275344
South_Bounding_Coordinate: 22.758046

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

Place:

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

Place:

Place_Keyword_Thesaurus: CoRIS Place Thesaurus
Place_Keyword:

COUNTRY/TERRITORY > United States of America > Hawaii > Honolulu > Nihoa (23N161W0001)

Place_Keyword:

OCEAN BASIN > Pacific Ocean > Central Pacific Ocean > Northwestern Hawaiian Islands > Nihoa (23N161W0001)

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 (JIMAR) 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:

http://www.soest.hawaii.edu/pibhmc/NWHI_images/Nihoa_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: 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: Variable, see process description Horizontal position accuracy: Variable, see process description

Vertical_Positional_Accuracy:

Vertical_Positional_Accuracy_Report:

Variable, see process description Raw sounding resolution: Variable, see process description

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. 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. The netCDF grid file is 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: 20070105

Spatial_Data_Organization_Information:

Direct_Spatial_Reference_Method: Raster
Raster_Object_Information:

Raster_Object_Type: Grid Cell
Row_Count: 2768
Column_Count: 4805
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: 4
Transverse_Mercator:

Scale_Factor_at_Central_Meridian: 0.9996
Longitude_of_Central_Meridian: -159
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
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/Nihoa_20m.asc.zip

Fees: None

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

Metadata: