Nadir Photographs Taken During Low-Altitude Transects of the Arctic Network of National Park Units and Selawik National Wildlife Refuge, Alaska, July 2013

Identification_Information:

Citation:

Citation_Information:

Originator: Marcot, Bruce G. (ORCID: 0000-0002-3667-7481)
Originator: Jorgenson, M. Torre (ORCID: 0000-0002-9834-8851)
Originator: DeGange, Anthony R.
Publication_Date: 20140521
Title:

Geospatial_Data_Presentation_Form: digital photographic images
Series_Information:

Series_Name:

Low-Altitude Photographic Transects of the Arctic Network of National Park Units and Selawik National Wildlife Refuge, Alaska, July 2013

Issue_Identification: ver 1.1, March 2023

Publication_Information:

Publication_Place: Anchorage, Alaska
Publisher: U.S. Geological Survey, Alaska Science Center

Other_Citation_Details:

Suggested Citation: Marcot, B.G., Jorgenson, M.T., DeGange, A.R., 2014, Low-altitude photographic transects of the Arctic Network of National Park Units and Selawik National Wildlife Refuge, Alaska, July 2013 (ver 1.1, March 2023): U.S. Geological Survey data release, https://doi.org/10.5066/P9KFIRWQ

Online_Linkage: https://doi.org/10.5066/P9KFIRWQ
Larger_Work_Citation:

Citation_Information:

Originator: U.S. Geological Survey, Alaska Science Center
Publication_Date: 2009
Title: The WILDlife Potential Habitat ForeCASTing Framework (WildCast)
Geospatial_Data_Presentation_Form: website
Series_Information:

Series_Name: Alaska Science Portal
Issue_Identification: 349

Publication_Information:

Publication_Place: Anchorage, Alaska
Publisher: U.S. Geological Survey, Alaska Science Center

Other_Citation_Details:

This is a link to the broader USGS Alaska Science Center research project supported by these data. Users will find a description of the research project and links to associated reports, publications, and data products.

Online_Linkage: http://alaska.usgs.gov/portal/project.php?project_id=349

Description:

Abstract:

This dataset contains aerial nadir digital photos and ecotype classification data determined from the photos. Aerial nadir photos were taken at 5 second intervals of the arctic landscape during low altitude photo survey transects in northwest Alaska, July 2013. Three flight transects were conducted from small aircraft over the National Park Service's Arctic Network (ARCN; Bering Land Bridge National Preserve, Cape Krusenstern National Monument, Gates of the Arctic National Park and Preserve, Kobuk Valley National Park, and Noatak National Preserve) and the U.S. Fish and Wildlife Service's Selawik National Wildlife Refuge.

Purpose:

Three aerial photo transects were conducted in July 2013, to provide photos of current conditions and prevalence of land cover types as a baseline for measuring future change, and to complement the existing grid-based sample photography of the region (Swanson 2013).

Supplemental_Information:

Extensive details of all aspects of the aerial photographic, video, and GPS data collection and processing are provided in Marcot et al. 2014.

The study area included five units of the National Park Service's Arctic Network (ACRN; Bering Land Bridge National Preserve, Cape Krusenstern National Monument, Gates of the Arctic National Park and Preserve, Kobuk Valley National Park, and Noatak National Preserve), the adjacent area of U.S. Fish and Wildlife Service's Selawik National Wildlife Refuge, and a 10-km buffer around all of these administrative units, totaling 162,868 km2 in an area spanning roughly 500 km east to west and 300 km north to south. This is also the study area for the USGS Wildlife Potential Habitat Forecasting Framework Project (WildCast) that projects effects of climate change on future land cover and wildlife habitat (DeGange et al. 2013)

Time_Period_of_Content:

Time_Period_Information:

Range_of_Dates/Times:

Beginning_Date: 20130716
Ending_Date: 20130718

Currentness_Reference: observed

Status:

Progress: Complete
Maintenance_and_Update_Frequency: None planned

Spatial_Domain:

Bounding_Coordinates:

West_Bounding_Coordinate: -169.22
East_Bounding_Coordinate: -149.05
North_Bounding_Coordinate: 68.87
South_Bounding_Coordinate: 64.78

Keywords:

Theme:

Theme_Keyword_Thesaurus: USGS Metadata Identifier
Theme_Keyword: USGS:ASC11

Theme:

Theme_Keyword_Thesaurus: ISO 19115 Topic Category
Theme_Keyword: Biota
Theme_Keyword: Environment
Theme_Keyword: ImageryBaseMapsEarthCover
Theme_Keyword: GeoscientificInformation
Theme_Keyword: InlandWaters

Theme:

Theme_Keyword_Thesaurus: NASA GCMD Earth Science Keyword Thesaurus
Theme_Keyword: Land Surface
Theme_Keyword: Frozen Ground
Theme_Keyword: Geomorphic Landforms/Processes
Theme_Keyword: Landscape
Theme_Keyword: Land Use/Land Cover

Theme:

Theme_Keyword_Thesaurus: USGS Thesaurus
Theme_Keyword: Image Analysis
Theme_Keyword: Aerial Photography
Theme_Keyword: Videography
Theme_Keyword: Image Collections
Theme_Keyword: Geography
Theme_Keyword: Climate Change
Theme_Keyword: Land Use and Land Cover
Theme_Keyword: Vegetation
Theme_Keyword: Tundra Ecosystems
Theme_Keyword: Coastal Ecosystems

Theme:

Theme_Keyword_Thesaurus: None
Theme_Keyword: Photogrammetry
Theme_Keyword: Arctic Network
Theme_Keyword: Low Altitude Air Photo
Theme_Keyword: Low Altitude Video
Theme_Keyword: Northwest Alaska
Theme_Keyword: Land Cover
Theme_Keyword: Ecotypes

Place:

Place_Keyword_Thesaurus: USGS Geographic Names Information System (GNIS)
Place_Keyword: Alaska
Place_Keyword: Northwest Arctic Borough

Place:

Place_Keyword_Thesaurus: None
Place_Keyword: Bering Land Bridge National Preserve
Place_Keyword: Selawik National Wildlife Refuge
Place_Keyword: Cape Krusenstern National Monument
Place_Keyword: Gates of the Arctic National Park
Place_Keyword: Gates of the Arctic National Preserve
Place_Keyword: Kobuk Valley National Park
Place_Keyword: Noatak National Preserve

Access_Constraints: None
Use_Constraints:

It is requested that the authors, the USGS Alaska Science Center, the National Park Service and the US Forest Service Pacific Northwest Research Station be cited for any subsequent publications referenced to this dataset.

Point_of_Contact:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization: U.S. Geological Survey, Alaska Science Center

Contact_Address:

Address_Type: Mailing and Physical
Address: 4210 University Drive
City: Anchorage
State_or_Province: Alaska
Postal_Code: 99508
Country: USA

Contact_Voice_Telephone: 907-786-7000
Contact_Electronic_Mail_Address: ascweb@usgs.gov

Data_Set_Credit:

USGS Alaska Science Center, National Park Service, US Forest Service Pacific Northwest Research Station

Cross_Reference:

Citation_Information:

Originator: Marcot, B.G.
Originator: Jorgenson, M.T.
Originator: DeGange, A.R.
Publication_Date: 2014
Title:

Low-Altitude Photographic Transects of the Arctic Network of National Park Units and Selawik National Wildlife Refuge, Alaska, July 2013

Geospatial_Data_Presentation_Form: document
Series_Information:

Series_Name: U.S. Geological Survey Data Series
Issue_Identification: 846

Publication_Information:

Publication_Place: online
Publisher: U.S. Geological Survey

Other_Citation_Details:

Marcot, B.G., Jorgenson, M.T., DeGange, A.R. 2014. Low-altitude photographic transects of the Arctic Network of National Park Units and Selawik National Wildlife Refuge, Alaska, July 2013: U.S. Geological Survey Data Series 846 https://doi.org/10.3133/ds846

Online_Linkage: https://doi.org/10.3133/ds846

Cross_Reference:

Citation_Information:

Originator: DeGange, A.
Originator: Marcot, B.G.
Originator: Lawler, J.
Originator: Jorgenson, T.
Originator: Winfree, R.
Publication_Date: 2013
Title:

Predicting the effects of climate change on ecosystems and wildlife habitat in northwest Alaska—Results of the WildCast project

Geospatial_Data_Presentation_Form: document
Series_Information:

Series_Name: Alaska Park Science
Issue_Identification: 12(2)66–73

Publication_Information:

Publication_Place: online
Publisher: National Park Service

Other_Citation_Details:

DeGange, A., Marcot, B.G., Lawler, J., Jorgenson, T., and Winfree, R., 2013, Predicting the effects of climate change on ecosystems and wildlife habitat in northwest Alaska—Results of the WildCast project: Alaska Park Science 12(2)66–73

Online_Linkage: https://www.nps.gov/articles/aps-v12-i2-c12.htm

Data_Quality_Information:

Attribute_Accuracy:

Attribute_Accuracy_Report:

These are aerial photos. The Drift camera photos were approximately 50% obscured by the right float of the aircraft during the Bering transect. The photos for the remaining transects are free of obstructions. During image processing, date and time of each photograph's EXIF (exchangeable image file format) metadata were checked for accuracy, as these data were correlated with the positions acquired from an on-board GPS and used for geotagging each photograph.

Logical_Consistency_Report: Attribute values fall within expected ranges
Completeness_Report:

Extensively redundant or extraneous photographs were deleted, such as time-lapse photos taken when the planes were stationary, long sequences when over deep water (e.g., over Kotzebue Sound), and other photos with no usable content.

Positional_Accuracy:

Horizontal_Positional_Accuracy:

Horizontal_Positional_Accuracy_Report:

GPS waypoints were recorded automatically at five second intervals using an i-gotU GT-120 GPS waypoint data logger mounted on each airplane's dashboard and a Garmin Oregon 550t hand-held unit (published horizontal accuracy less than 10 m).

Lineage:

Source_Information:

Source_Citation:

Citation_Information:

Originator: Marcot, B.G.
Originator: Jorgenson, M.T.
Originator: DeGange, A.R.
Publication_Date: 2014
Title:

Low-Altitude Photographic Transects of the Arctic Network of National Park Units and Selawik National Wildlife Refuge, Alaska, July 2013

Geospatial_Data_Presentation_Form: document
Series_Information:

Series_Name: U.S. Geological Survey Data Series
Issue_Identification: 846

Publication_Information:

Publication_Place: online
Publisher: U.S. Geological Survey

Other_Citation_Details:

Online_Linkage: https://doi.org/10.3133/ds846

Type_of_Source_Media: Publication
Source_Time_Period_of_Content:

Time_Period_Information:

Single_Date/Time:

Calendar_Date: 2014

Source_Currentness_Reference: publication date

Source_Citation_Abbreviation: Marcot et al. 2014
Source_Contribution:

Provides extensive details of all aspects of the aerial photographic, video, and GPS data collection and processing.

Source_Information:

Source_Citation:

Citation_Information:

Originator: Jorgenson, M.T.
Originator: Roth, J.E.
Originator: Miller, P.F.
Originator: Macander, M.J.
Originator: Duffy, M.S.
Originator: Wells, A.F.
Originator: Frost, G.V.
Originator: Pullman, E.R.
Publication_Date: 2009
Title:

An Ecological Land Survey and Landcover Map of the Arctic Network

Geospatial_Data_Presentation_Form: document
Series_Information:

Series_Name: Natural Resource Technical Report NPS/ARCN/NRTR
Issue_Identification: 2009/270

Publication_Information:

Publication_Place: Fort Collins, Colorado
Publisher: National Park Service, Natural Resource Program Center

Other_Citation_Details:

Jorgenson, M.T., Roth, J.E., Miller, P.F., Macander, M.J., Duffy, M.S., Wells, A.F., Frost, G.V., Pullman, E.R. 2009. An ecological land survey and landcover map of the Arctic Network. Natural Resource Technical Report. NPS/ARCN/NRTR—2009/270. National Park Service, Natural Resource Stewardship and Science, Fort Collins, Colorado.

Published report archived by U.S. National Park Service Catalog (IRMA Data Store) https://irma.nps.gov/DataStore [reference code: 663934] and the Alaska Resources Library and Information Services (ARLIS) https://www.arlis.org [reference code: ILS:642073521]

Online_Linkage: https://irma.nps.gov/DataStore/Reference/Profile/663934

Type_of_Source_Media: Publication
Source_Time_Period_of_Content:

Time_Period_Information:

Single_Date/Time:

Calendar_Date: 2009

Source_Currentness_Reference: publication date

Source_Citation_Abbreviation: Jorgenson et al. 2009
Source_Contribution: Used to determine ecotypes in aerial nadir photos.

Source_Information:

Source_Citation:

Citation_Information:

Originator: Swanson, D.K.
Publication_Date: 2013
Title:

Three decades of landscape change in Alaska’s Arctic National Parks—Analysis of aerial photographs, c. 1980–2010

Geospatial_Data_Presentation_Form: document
Series_Information:

Series_Name: National Park Service, Natural Resource Technical Report
Issue_Identification: NPS/ARCN/NRTR—2013/668

Publication_Information:

Publication_Place: online
Publisher: 2010: National Park Service

Other_Citation_Details:

Swanson, D.K., 2013, Three decades of landscape change in Alaska’s Arctic National Parks—Analysis of aerial photographs, c. 1980–2010: National Park Service, Natural Resource Technical Report NPS/ARCN/NRTR—2013/668, 38 p.

Published report archived by U.S. National Park Service Catalog (IRMA Data Store) https://irma.nps.gov/DataStore [reference code: 2192701]

Online_Linkage: https://irma.nps.gov/DataStore/Reference/Profile/2192701

Type_of_Source_Media: Publication
Source_Time_Period_of_Content:

Time_Period_Information:

Single_Date/Time:

Calendar_Date: 2013

Source_Currentness_Reference: publication date

Source_Citation_Abbreviation: Swanson 2013
Source_Contribution: Describes existing grid-based sample photography of the region.

Source_Information:

Source_Citation:

Citation_Information:

Originator: DeGange, A.
Originator: Marcot, B.G.
Originator: Lawler, J.
Originator: Jorgenson, T.
Originator: Winfree, R.
Publication_Date: 2013
Title:

Predicting the effects of climate change on ecosystems and wildlife habitat in northwest Alaska—Results of the WildCast project

Geospatial_Data_Presentation_Form: document
Series_Information:

Series_Name: Alaska Park Science
Issue_Identification: 12(2)66–73

Publication_Information:

Publication_Place: online
Publisher: National Park Service

Other_Citation_Details:

Online_Linkage: hhttps://www.nps.gov/articles/aps-v12-i2-c12.htm

Type_of_Source_Media: Publication
Source_Time_Period_of_Content:

Time_Period_Information:

Single_Date/Time:

Calendar_Date: 2013

Source_Currentness_Reference: publication date

Source_Citation_Abbreviation: DeGange et al. 2013
Source_Contribution:

Provides information about the Wildlife Potential habitat Forecasting Framework (Wildcast) project.

Source_Information:

Source_Citation:

Citation_Information:

Originator: Marcot, B.G.,
Originator: Jorgenson, M.T.
Originator: DeGange, A.R.
Publication_Date: 2016
Title: Wildlife Potential habitat Forecasting Framework (Wildcast)
Geospatial_Data_Presentation_Form: website
Publication_Information:

Publication_Place: Anchorage, Alaska
Publisher: U.S. Geological Survey, Alaska Science Center

Other_Citation_Details: Study information website
Online_Linkage:

https://www.usgs.gov/centers/asc/science/wildlife-potential-habitat-forecasting-framework-wildcast

Type_of_Source_Media: website
Source_Time_Period_of_Content:

Time_Period_Information:

Single_Date/Time:

Calendar_Date: 2016

Source_Currentness_Reference: publication date

Source_Citation_Abbreviation: Marcot et al. 2016
Source_Contribution:

Provides information about the Wildlife Potential habitat Forecasting Framework (Wildcast) project.

Process_Step:

Process_Description:

Extensive details of all aspects of the aerial photographic, video, and GPS data collection and processing are provided in Marcot et al. 2014.

Process_Date: Unknown

Process_Step:

Process_Description:

Oblique and nadir photographs and videos were shot along flight routes conducted July 16-18, 2013, totaling 17 h 46 m flight time and 2,590 km flight distance, at a mean altitude of approximately 300 m above ground level. Flight routes were selected to provide a broad representation of land cover types within each unit and to overfly specific locations of recent disturbances. Photographs were geotagged; all nadir photographs and videos were corrected for image lens distortion and appearance (increased gamma and color enhancement); oblique photographs were not corrected for appearance

Process_Date: Unknown

Process_Step:

Process_Description:

Process_Date: Unknown

Process_Step:

Process_Description:

Aerial nadir photos were taken with: (1) Drift HD-170 (focal length 5.00 mm) and (2) GoPro Hero3 Black Edition (focal length 2.77 mm) at 5 second intervals.

Process_Date: Unknown

Process_Step:

Process_Description:

Raw photographs were organized into folders, renamed by flight date and camera type.

Process_Date: Unknown

Process_Step:

Process_Description:

Process_Date: Unknown

Process_Step:

Process_Description:

Date and time stamps in each photograph file's EXIF metadata were checked for accuracy and correlated to the GPS waypoints for geotagging each photograph.

Process_Date: Unknown

Process_Step:

Process_Description:

Each photograph was adjusted for color saturation and gamma, which served to highlight many details.

Process_Date: Unknown

Process_Step:

Process_Description:

EXIF metadata from all photograph files were extracted and organized in tables (CSV format). Data include photograph file and directory name, photograph date and time, camera type and settings, geotagged digital latitude and longitude, and altitude above mean sea level.

Process_Date: Unknown

Process_Step:

Process_Description:

Each nadir photograph was corrected for lens distortion to adjust for their wide-angle (170d fisheye lens) distortion that occurred from the small focal lengths, and cropped to exclude blank portions of the image that occur after fisheye correction.

Process_Date: Unknown

Process_Step:

Process_Description:

The individual photograph geolocations were intersected in GIS with a digital elevation model (DEM) of the ARCN study area so that ground-level elevation could be determined for each photograph location. Then, the difference between flight altitude above mean sea level (determined enroute via the on-board GPS unit) and ground-level elevation gave flight elevation above ground level for all photographs, which was used to verify the mean flight elevation used in the calculations of photograph time-lapse intervals and areal coverage of each photograph.

Process_Date: Unknown

Process_Step:

Process_Description:

Using the geographic coordinates (latitude and longitude) each nadir photograph was overlaid in GIS (ArcMap 10.0) onto a map of ecotypes of the ARCN region (Jorgenson et al. 2009). Within a square window centered in each photograph, the number of pixels intersecting each ecotype was counted and recorded in the table with EXIF metadata.

Process_Date: Unknown

Spatial_Data_Organization_Information:

Direct_Spatial_Reference_Method: Point

Spatial_Reference_Information:

Horizontal_Coordinate_System_Definition:

Geographic:

Latitude_Resolution: 0.000001
Longitude_Resolution: 0.000001
Geographic_Coordinate_Units: Decimal degrees

Geodetic_Model:

Horizontal_Datum_Name: World Geodetic System of 1984 (WGS84)
Ellipsoid_Name: World Geodetic System of 1984 (WGS84)
Semi-major_Axis: 6378137
Denominator_of_Flattening_Ratio: 298.257223563

Vertical_Coordinate_System_Definition:

Altitude_System_Definition:

Altitude_Datum_Name: National Geodetic Vertical Datum of 1929
Altitude_Resolution: 1.00
Altitude_Distance_Units: meters
Altitude_Encoding_Method: Implicit coordinate

Entity_and_Attribute_Information:

Detailed_Description:

Entity_Type:

Entity_Type_Label: imageNadir_EXIFmetadataEcotype_[park/refuge].csv
Entity_Type_Definition:

Three tables with image metadata (retrieved from the digital photo's embedded EXIF metadata), the geographic coordinates of the image center point (determined by correlation of image timestamp and GPS track data), and the number of pixels in the image which occur in one of the defined ecotypes (determined with GIS by overlaying the image onto a map of named ecotypes). Presented in a Comma Separated Value (CSV) formatted tables.

File naming convention: imageNadir_EXIFmetadataEcotype_[park/refuge].csv Where: [park/refuge] = represents the location name of the flight transect.

Entity_Type_Definition_Source: Author defined

Attribute:

Attribute_Label: Filename
Attribute_Definition:

Filename of each photo. Corresponds to the filenames in the folders included with this data package.

File naming convention: ARCN [Date] [park/refuge] [Camera] [number]_pt.jpg: where: [Date] = date photo was taken (yymmdd); [park/refuge] = location name of the flight transect; [Camera] = make of the camera used; [Number] = sequential photo number

Attribute_Definition_Source: Author defined
Attribute_Domain_Values:

Unrepresentable_Domain: Filename of each photo

Attribute:

Attribute_Label: Datetime
Attribute_Definition:

Date and time (YY:MM:DD HH:MM:SS) when the photograph was taken.

Attribute_Definition_Source: Author defined
Attribute_Domain_Values:

Unrepresentable_Domain:

Date and time (YY:MM:DD HH:MM:SS) when the photograph was taken.

Attribute:

Attribute_Label: Camera_make
Attribute_Definition: Manufacturer (make) of the camera used to take the photograph.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:

Unrepresentable_Domain: Manufacturer (make) of the camera used to take the photograph.

Attribute:

Attribute_Label: Camera_model
Attribute_Definition: Model of the camera used to take the photograph.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:

Unrepresentable_Domain: Model of the camera used to take the photograph.

Attribute:

Attribute_Label: HeightWidth_pixels
Attribute_Definition: Size of the digital image in pixels.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:

Unrepresentable_Domain: Size of the digital image in pixels.

Attribute:

Attribute_Label: Image_size_pixels
Attribute_Definition: Number of pixels of the digital image (= height x width).
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:

Unrepresentable_Domain: Number of pixels of the digital image (= height x width).

Attribute:

Attribute_Label: Exposure_sec
Attribute_Definition: Shutter speed in seconds.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:

Unrepresentable_Domain: Shutter speed in seconds.

Attribute:

Attribute_Label: Aperture_F-number
Attribute_Definition: F-stop of the exposure.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:

Unrepresentable_Domain: F-stop of the exposure.

Attribute:

Attribute_Label: ISO
Attribute_Definition:

Sensitivity ("film speed") setting of the exposure (ISO = International Organization of Standardization).

Attribute_Definition_Source: Author defined
Attribute_Domain_Values:

Unrepresentable_Domain: Sensitivity setting of the exposure.

Attribute:

Attribute_Label: Flash
Attribute_Definition: Whether camera flash was used for the exposure.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:

Enumerated_Domain:

Enumerated_Domain_Value: No
Enumerated_Domain_Value_Definition: The flash was not used
Enumerated_Domain_Value_Definition_Source: Author defined

Attribute:

Attribute_Label: Distance
Attribute_Definition: Distance setting of the camera.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum: 0
Range_Domain_Maximum: 1

Attribute:

Attribute_Label: Focal_length
Attribute_Definition: Focal length setting for the exposure.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum: 3
Range_Domain_Maximum: 5

Attribute:

Attribute_Label: Latitude
Attribute_Definition:

Latitude at the center of the photograph, determined by correlation of image timestamp and GPS track data.

Attribute_Definition_Source: Author defined
Attribute_Domain_Values:

Unrepresentable_Domain: Latitude at the center of the photograph.

Attribute:

Attribute_Label: Longitude
Attribute_Definition:

Longitude at the center of the photograph, determined by correlation of image timestamp and GPS track data.

Attribute_Definition_Source: Author defined
Attribute_Domain_Values:

Unrepresentable_Domain: Longitude at the center of the photograph.

Attribute:

Attribute_Label: Flight_altitude_ASL_m
Attribute_Definition:

Altitude of the airplane above sea level (ASL) when the photograph was taken, in meters.

Attribute_Definition_Source: Author defined
Attribute_Domain_Values:

Unrepresentable_Domain: Altitude of the airplane above sea level (ASL)

Attribute:

Attribute_Label: DEM_elevation_m
Attribute_Definition:

Ground-level elevation at the center of the photograph, as taken from a digital elevation model (DEM) map in the ArcMap geographic information system, in meters.

Attribute_Definition_Source: Author defined
Attribute_Domain_Values:

Unrepresentable_Domain:

Ground-level elevation at the center of the photograph, as taken from a digital elevation model (DEM) map.

Attribute:

Attribute_Label: Flight_altitude_AGL_m
Attribute_Definition:

Altitude of the airplane above ground level (AGL) at the center of the photograph, in meters. Calculated as: (Flight_altitude_ASL_m) – (DEM_elevation_feet) / 3.281 feet/meter)

Attribute_Definition_Source: Author defined
Attribute_Domain_Values:

Unrepresentable_Domain: Altitude of the airplane above ground level (AGL).

Attribute:

Attribute_Label: Alpine_Lake through Upland_Sandy_Dry_Alkaline_Barrens
Attribute_Definition:

These 43 columns provide number of pixels within the image classified as the named ecotype. Blank cells indicate that the image does not contain pixels of the named ecotype.

Attribute_Definition_Source: Author defined
Attribute_Domain_Values:

Unrepresentable_Domain:

Number of pixels within the image classified as the named ecotype.

Detailed_Description:

Entity_Type:

Entity_Type_Label: imageNadir_[park/refuge]
Entity_Type_Definition:

Folders (with sub-folders) containing aerial nadir photos of the arctic landscape from low altitude transects; taken at 5 second intervals from Drift HD-170 and GoPro Hero3 cameras. Embedded image EXIF metadata include camera information and the geographic coordinates of the center point of the image (determined by correlation of image timestamp and GPS track data). Presented in JPG format. Folders and sub-folders are grouped by flight transect location and camera make.

File naming convention: ARCN [Date] [park/refuge] [Camera] [number]_pt.jpg Where: [Date] = date photo was taken (yymmdd); [park/refuge] = location name of the flight transect; [Camera] = make of the camera used; [Number] = sequential photo number

Entity_Type_Definition_Source: Author defined

Nadir Photographs Taken During Low-Altitude Transects of the Arctic Network of National Park Units and Selawik National Wildlife Refuge, Alaska, July 2013

Metadata: