Vectorized Lead Segmentation covering the Chukchi and Beaufort Seas offshore of Northern Alaska, USA and Northwest Canada.

Metadata:

• Identification_Information
• Data_Quality_Information
• Spatial_Data_Organization_Information
• Spatial_Reference_Information
• Entity_and_Attribute_Information
• Distribution_Information
• Metadata_Reference_Information

Identification_Information:

Citation:

Citation_Information:

Originator: University of Alaska Fairbanks

Publication_Date: 20051231

Title:

Vectorized Lead Segmentation covering the Chukchi and Beaufort Seas offshore of Northern Alaska, USA and Northwest Canada.

Geospatial_Data_Presentation_Form: vector digital data

Online_Linkage: <http://mms.gina.alaska.edu>

Description:

Abstract:

This vector based data set was derived from an ArcGIS grid (of 1.1 km cells) and represents spring leads along the coast of Northern Alaska (West of Barrow) and Northwest Canada (East of the Mackenzie Delta) for the study area which ranges from approximately 130 to 164 degrees West and 68.5 to 74 degrees North.

Purpose:

This data was compiled by the University of Alaska Fairbanks to meet contract requirements for the US Mineral Management Service: Mapping and Characterization of Recurring Spring Leads and Landfast ice in the Beaufort and Chukchi Seas (AK-03-06)

Supplemental_Information:

For the purposes of the MMS study, the file names associated with Band 1 data (visual) are prefixed with a "v" and Band 4 files (thermal) prefixed with a "t". The day of the year, hour and minutes are incorporated in the file names. For descriptive purposes the following abbreviations are used as placeholders for real values to illustrate the naming convention: d = day of year Y = Year T = time in GMT A Band 1 shapefile follows this convention: v d d d _T T T Tshape A Band 4 shapefile follows this convention: t d d d _T T T Tshape Examples of these file names are v015_1012shape and t015_1012shape

Time_Period_of_Content:

Time_Period_Information:

Range_of_Dates/Times:

Beginning_Date: 197201

Ending_Date: unknown

Currentness_Reference: ground condition

Status:

Progress: In work

Maintenance_and_Update_Frequency: As needed

Spatial_Domain:

Bounding_Coordinates:

West_Bounding_Coordinate: -164.176389

East_Bounding_Coordinate: -129.978654

North_Bounding_Coordinate: 73.947199

South_Bounding_Coordinate: 68.481396

Keywords:

Theme:

Theme_Keyword_Thesaurus: Aquatic Sciences and Fisheries Thesaurus

Theme_Keyword: spring leads

Theme_Keyword: sea ice

Theme_Keyword: lead

Place:

Place_Keyword_Thesaurus: Dictionary of Alaska Place Names

Place_Keyword: Arctic Ocean

Place_Keyword: Chukchi Sea

Place_Keyword: Beaufort Sea

Place_Keyword: North Slope

Place_Keyword: Alaska

Place_Keyword: Canada

Access_Constraints: None.

Use_Constraints:

Any hardcopies or published information utilizing these data sets shall clearly indicate their source. If the user has modified the data in any way they are obligated to describe the types of modifications that they have performed. User specifically agrees not to misrepresent these datasets, nor to imply that any changes that they made were approved by the University of Alaska.

Point_of_Contact:

Contact_Information:

Contact_Person_Primary:

Contact_Person: Dr. Hajo Eicken

Contact_Organization: Geophysical Institute

Contact_Position: Unversity of Alaska Fairbanks

Contact_Address:

Address_Type: mailing and physical address

Address: 903 Koyukuk Dr., P.O. Box 757320

City: Fairbanks

State_or_Province: Alaska

Postal_Code: 99775-7320

Country: USA

Contact_Voice_Telephone: 907-474-7280

Contact_Facsimile_Telephone: 907-474-7290

Contact_Electronic_Mail_Address: hajo.eicken@gi.alaska.edu

Browse_Graphic:

Browse_Graphic_File_Name: *.jpg

Browse_Graphic_File_Description: Low resolution browse graphic of shapefile

Browse_Graphic_File_Type: JPEG

Data_Set_Credit:

The funding for this effort was provided by the US Mineral Management Service for Mapping and Characterization of Recurring Spring Leads and Landfast ice in the Beaufort and Chukchi Seas (AK-03-06, MMS-71707)

Native_Data_Set_Environment:

Microsoft Windows 2000 Version 5.0 (Build 2195) Service Pack 4; ESRI ArcCatalog 8.3.0.800

Data_Quality_Information:

Logical_Consistency_Report:

Map projection and datum were confirmed and checked to conform with base data sets and imagery.

Completeness_Report: Complete.

Positional_Accuracy:

Horizontal_Positional_Accuracy:

Horizontal_Positional_Accuracy_Report:

The International Observatory of the North (ION) uses satellite navigation and attitude parameters for scene navigation (with additional ground control) to produce adequate results (with errors <3 km) for geolocated AVHRR imagery. ION data sets were used as a base map to derive the lead segmentation.

Quantitative_Horizontal_Positional_Accuracy_Assessment:

Horizontal_Positional_Accuracy_Value: 3000 meters

Horizontal_Positional_Accuracy_Explanation: Visual inspection. Distance measurement tools.

Lineage:

Process_Step:

Process_Description:

AVHRR data was geolocated, calibrated and reprojected in GeoTIFF format using TeraScan software. A coast mask is applied in ENVI. The fraction of leads within each pixel is then determined based on the brightness temperatures or reflectances of open water and the surrounding thick ice, as described by Lindsay and Rothrock (Arctic sea ice leads from advanced very high resolution radiometer images. Journal of Geophysical Research, 100(C3), 4533-4544, 1995). Here, we have corrected for regional differences in surface temperature and reflectance as well as thin cloud cover by determining the fraction of leads within a moving 50 by 50 pixel (55 x 55 km) square window, with the fraction of thick ice based on the upper and lower quartile reflectance and brightness temperature, respectively. For a few cases of more expansive stretches of open water, manual adjustments of open water extent have been made. The resulting image indicating the fraction of open water is then binarized about a threshold corresponding to an open water fraction of 25% in each pixel, with pixels containing less open water designated as ice and those at or above 25% designated as leads. This information is then brought into NIH Image for derivation of lead location, shape and size statistics, open water fractions and other information for the different study subregions.

An IDL script was used to export the binarized files into GeoTiff format. The batch utility within ArcToolbox was used to convert GeoTiffs to ArcGIS Grid format. A batch file was used in ArcCatalog to define the map projection and datum. Each Grid file was then converted to an ArcGIS Coverage file and then Shapefile using batch utilities within ArcToolbox. Low resolution browse images (*.jpg format) were generated for display on the project web site. Final processing included a batch import of the appropriate FGDC compliant metadata template. Final data sets were bundled with Winzip for posting to the web to ensure clean data transfer of the components of the shapefile, plus associated metadata record and browse image.

Process_Date: 2004

Process_Contact:

Contact_Information:

Contact_Person_Primary:

Contact_Person: Dr. Hajo Eicken

Contact_Organization: University of Alaska Fairbanks, Geophysical Institute

Contact_Position: Associate Professor

Contact_Address:

Address_Type: mailing and physical address

Address: 903 Koyukuk Dr., P.O. Box 757320

City: Fairbanks

State_or_Province: AK

Postal_Code: 99775-7320

Country: USA

Contact_Voice_Telephone: 907-474-7196

Contact_Facsimile_Telephone: 907-474-7290

Contact_Electronic_Mail_Address: Hajo.Eicken@gi.alaska.edu

Hours_of_Service: business hours

Spatial_Data_Organization_Information:

Direct_Spatial_Reference_Method: Vector

Point_and_Vector_Object_Information:

SDTS_Terms_Description:

SDTS_Point_and_Vector_Object_Type: G-polygon

Point_and_Vector_Object_Count: 1564

Spatial_Reference_Information:

Horizontal_Coordinate_System_Definition:

Planar:

Map_Projection:

Map_Projection_Name: Albers Conical Equal Area

Albers_Conical_Equal_Area:

Standard_Parallel: 55.000000

Standard_Parallel: 65.000000

Longitude_of_Central_Meridian: -154.000000

Latitude_of_Projection_Origin: 50.000000

False_Easting: 0.000000

False_Northing: 0.000000

Planar_Coordinate_Information:

Planar_Coordinate_Encoding_Method: coordinate pair

Coordinate_Representation:

Abscissa_Resolution: 0.002048

Ordinate_Resolution: 0.002048

Planar_Distance_Units: meters

Geodetic_Model:

Horizontal_Datum_Name: North American Datum of 1983

Ellipsoid_Name: Geodetic Reference System 80

Semi-major_Axis: 6378137.000000

Denominator_of_Flattening_Ratio: 298.257222

Entity_and_Attribute_Information:

Detailed_Description:

Entity_Type:

Entity_Type_Label: Spring Leads

Entity_Type_Definition: Band 1

Entity_Type_Definition_Source: ESRI

Attribute:

Attribute_Label: FID

Attribute_Definition: Feature ID of shapefile

Attribute_Definition_Source: ESRI

Attribute_Domain_Values:

Enumerated_Domain:

Enumerated_Domain_Value: FID

Enumerated_Domain_Value_Definition: Feature Identifier of Shapefile

Enumerated_Domain_Value_Definition_Source: ESRI

Attribute:

Attribute_Label: Shape

Attribute_Definition: Feature Class

Attribute_Definition_Source: ESRI

Attribute_Domain_Values:

Enumerated_Domain:

Enumerated_Domain_Value: Shape

Enumerated_Domain_Value_Definition: Feature Class = Polygon

Enumerated_Domain_Value_Definition_Source: ESRI

Attribute:

Attribute_Label: Area

Attribute_Definition: Area of polygon

Attribute_Definition_Source: ESRI

Attribute_Domain_Values:

Enumerated_Domain:

Enumerated_Domain_Value: Area

Enumerated_Domain_Value_Definition: Area of Polygon

Enumerated_Domain_Value_Definition_Source: Automatically calculated by ArcGIS

Attribute:

Attribute_Label: PERIMETER

Attribute_Definition: perimeter of polygon

Attribute_Definition_Source: ESRI

Attribute_Domain_Values:

Enumerated_Domain:

Enumerated_Domain_Value: Perimeter

Enumerated_Domain_Value_Definition: Perimeter of polygon

Enumerated_Domain_Value_Definition_Source: Automatically calculated by ArcGIS

Attribute:

Attribute_Label: _#######

Attribute_Definition: Internal Feature Number

Attribute_Definition_Source: ESRI

Attribute_Domain_Values:

Enumerated_Domain:

Enumerated_Domain_Value: _######

Enumerated_Domain_Value_Definition: Internal Feature Number

Enumerated_Domain_Value_Definition_Source: Residual Attribute Generated by conversion to ArcGIS Coverage

Attribute:

Attribute_Label: ######_ID

Attribute_Definition: Internal Identifier

Attribute_Definition_Source: ESRI

Attribute_Domain_Values:

Enumerated_Domain:

Enumerated_Domain_Value: ######_ID

Enumerated_Domain_Value_Definition: Internal Identifier

Enumerated_Domain_Value_Definition_Source: Residual Attribute Generated by conversion to ArcGIS Coverage

Attribute:

Attribute_Label: GRID_CODE

Attribute_Definition: Grid code for cell value

Attribute_Definition_Source: ESRI

Attribute_Domain_Values:

Enumerated_Domain:

Enumerated_Domain_Value: Value = 255

Enumerated_Domain_Value_Definition: ice

Enumerated_Domain_Value_Definition_Source: Derived from binary classification of AVHRR source imagery.

Enumerated_Domain:

Enumerated_Domain_Value: Value = 0

Enumerated_Domain_Value_Definition: leads

Enumerated_Domain_Value_Definition_Source: Binarized classification of AVHRR source imagery.

Distribution_Information:

Distributor:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization: UAF Geographic Information Network of Alaska (GINA)

Contact_Person: Dr. Virgil (Buck) Sharpton

Contact_Position: President's Professor of Remote Sensing

Contact_Address:

Address_Type: mailing and physical address

Address: 903 Koyukuk Drive

City: Fairbanks

State_or_Province: Alaska

Postal_Code: 99775-7320

Country: USA

Contact_Voice_Telephone: 907.474.6663

Contact_Electronic_Mail_Address: buck.sharpton@gina.alaska.edu

Hours_of_Service: 8:00 a.m. - 5:00 p.m. AST

Resource_Description: Downloadable Data

Distribution_Liability:

The University of Alaska makes no express or implied warranties (including warranties of merchantability and fitness) with respect to the character, function, or capabilities of the electronic services or products or their appropriateness for any users purposes. In no event will the University of Alaska be liable for any incidental, indirect, special, consequential or other damages suffered by the user or any other person or entity whether from the use of the electronic services or products, any failure thereof or otherwise, and in no event will the State of Alaska's liability to the requestor or anyone else exceed the fee paid for the electronic service or product.

Standard_Order_Process:

Digital_Form:

Digital_Transfer_Information:

Format_Name: ESRI ArcGIS format

Format_Version_Date: 200301101

Format_Specification: ESRI Grid / ESRI Shapefile

Transfer_Size: 0.826

Digital_Transfer_Option:

Online_Option:

Computer_Contact_Information:

Network_Address:

Network_Resource_Name: <http://mms.gina.alaska.edu>

Access_Instructions: web browser and/or FTP

Fees: None

Available_Time_Period:

Time_Period_Information:

Range_of_Dates/Times:

Beginning_Date: unknown

Ending_Date: unknown

Metadata_Reference_Information:

Metadata_Date: 20040915

Metadata_Contact:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization: Nuna Technologies

Contact_Person: Allison Graves Gaylord

Contact_Position: Owner / GIS Specialist

Contact_Address:

Address_Type: mailing address

Address: P.O. Box 1483

City: Homer

State_or_Province: AK

Postal_Code: 99723-1483

Country: USA

Contact_Voice_Telephone: 907.235.3476

Contact_Electronic_Mail_Address: nunatech@usa.net

Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata

Metadata_Standard_Version: FGDC-STD-001-1998

Metadata_Time_Convention: local time

Metadata_Access_Constraints: None.

Metadata_Use_Constraints:

If the user has modified the data in any way they are obligated to describe the types of modifications they have performed in the supporting metadata file. User specifically agrees not to imply that changes they made were approved by the University of Alaska.

Metadata_Security_Information:

Metadata_Security_Classification_System: None.

Metadata_Security_Classification: Unclassified

Metadata_Security_Handling_Description: None.

Metadata_Extensions:

Online_Linkage: <http://www.esri.com/metadata/esriprof80.html>

Profile_Name: ESRI Metadata Profile