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100-Meter Resolution Natural Earth of Alaska

Identification Information

Citation
Title
100-Meter Resolution Natural Earth of Alaska
Originator
Geological Survey (U.S.)
Publisher
National Atlas of the United States
Place of Publication
Rolla , Missouri , US
Publication Date
2013-07-01
Identifier
http://purl.stanford.edu/nr598jf9933
Geospatial Data Presentation Form
mapDigital
Collection Title
National Atlas of the United States of America, 1997-2014
Other Citation Details
These data were downloaded from the National Atlas website (http://www.nationalatlas.gov/atlasftp.html) in August 2014.
Abstract
This layer is a georeferenced raster image representing a natural-earth image of Alaska. The image is land cover in natural colors combined with shaded relief, which produces a naturalistic rendition of the Earth's surface. The data set is in an Albers Equal-Area Conic projection. The Natural Earth data were produced from existing National Atlas land cover, elevation, and satellite view data, as well as MODIS Vegetation Continuous Fields data. This layer is part of the 1997-2014 edition National Atlas of the United States.
Purpose
The 100-meter resolution Natural Earth data were developed to portray the terrain and land cover of the United States at 1:1,000,000 scale. They are intended primarily for visual purposes. The original NLCD data or Landsat Thematic Mapper imagery data should be used for conducting scientific analysis, and the original NED data should be used for determining the most accurate elevation values. No responsibility is assumed by the National Atlas of the United States in the use of these data.
Supplemental Information
Included with the GeoTIFF are an information file (.xml), an auxiliary information file (.aux.xml), an image overview file (.ovr), a .tfw file (more information included below), and a .prj file (more information included below.) The contents of the associated world file (.tfw) are: 100.0 0.0 0.0 -100.0 -3326950.0 2437950.0 The projection (.prj) file contains the following information: PROJCS["Albers_NAD83_Alaska", GEOGCS["GCS_North_American_1983", DATUM["D_North_American_1983", SPHEROID["GRS_1980",6378137.0,298.257222101]], PRIMEM["Greenwich",0.0], UNIT["Degree",0.0174532925199433]], PROJECTION["Albers"], PARAMETER["False_Easting",0.0], PARAMETER["False_Northing",0.0], PARAMETER["Central_Meridian",-154.0], PARAMETER["Standard_Parallel_1",55.0], PARAMETER["Standard_Parallel_2",65.0], PARAMETER["Latitude_Of_Origin",50.0], UNIT["Meter",1.0]] Data set extent in meters (Albers Equal-Area Conic projection) North 2438000 West -3327000 East 1654000 South 346000 There are no NULL or NODATA values in the GeoTIFF. Instead, all oceans are assigned a RGB color of (193, 224, 250) (blue) and all non-U.S. land is assigned a RGB color of (240, 235, 211) (tan). Information about National Atlas Web services can be found on the Web Map and Web Feature Services page; see http://nationalatlas.gov/infodocs/webservices.html.
Scale Denominator
1000000
Temporal Extent
Currentness Reference
Publication date
Time Instant
2013-08-01T00:00:00
Bounding Box
West
-180
East
180
North
71.954724
South
43.053445
ISO Topic Category
imageryBaseMapsEarthCover
elevation
Place Keyword
Alaska
Place Keyword Thesaurus
geonames
Temporal Keyword
2013
Theme Keyword
Land cover
Digital elevation models
Theme Keyword Thesaurus
lcsh
Legal Constraints
Use Limitation
Although these data have been processed successfully on a computer system at the U.S. Geological Survey, no warranty expressed or implied is made by the U.S. Geological Survey regarding the utility of the data on any other system, nor shall the act of distribution constitute any such warranty. No responsibility is assumed by the U.S. Geological Survey in the use of these data.
Use Restrictions
otherRestrictions
Other Restrictions
This item is in the public domain.
Status
completed
Maintenance and Update Frequency
notPlanned
Collection
Collection Title
National Atlas of the United States of America, 1997-2014
URL
http://purl.stanford.edu/cv275yx9215
Publication Date
1998-01-01
Language
eng
Credit
National Atlas of the United States. (2013). 100-Meter Resolution Natural Earth of Alaska. National Atlas of the United States. Available at: http://purl.stanford.edu/nr598jf9933.
Point of Contact
Contact
John Hutchinson
Delivery Point
47914 252nd Street
City
Sioux Falls
Administrative Area
South Dakota
Postal Code
57198-0001
Country
US
Email
atlasmail@usgs.gov
Phone
1 605 594 6049

Spatial Reference Information

Reference System Identifier
Code
3338
Code Space
EPSG
Version
8.6.2

Data Quality Information

Lineage
Process Step
Description
The Natural Earth image is a combination of land cover in natural colors and shaded relief. The shaded relief part of the image was created from the National Atlas Elevation data. Relief was rendered with Natural Scene Designer Pro 6.0. The original 100-meter data were down-sampled to 200 meters and received one application of smoothing in NSD Pro 6 prior to relief rendering. Light azimuth = 315 degrees, angle = 45 degrees. Relief in Alaska was rendered with 200 percent vertical exaggeration. Shaded relief was composited in Adobe Photoshop CS6. The Avenza Geographic Imager 4.1 plug-in for Photoshop maintained georeferencing of the shaded relief image. In Photoshop, the relief is composed of four layers that print above land cover: global illumination, high mountain illumination, global shadows, and high mountain shadows. Illumination prints as transparent white, global shadows as transparent black, and high mountain shadows as transparent gray blue. The land cover part of the image was derived from the National Atlas Land Cover and Satellite View data sets, and from the MODIS Vegetation Continuous Fields (VCF) data set. These products were re-colorized and blended in Photoshop to create land cover with natural colors. (While National Atlas Tree Canopy data were used for the Natural Earth data sets of the conterminous United States, Hawaii, and Puerto Rico and the U.S. Virgin Islands, in Alaska, MODIS VCF forest canopy data was used instead because NLCD Tree Canopy coverage was not complete statewide.) The Landsat images appear as subtle textures in cropland, wetland, and tundra areas. Glacier snouts in Alaska were enhanced with colorized Landsat textures (from Satellite View AK 100M) and manual drawing. Using dissolve blending mode in Photoshop for the Land Cover and MODIS VCF forest canopy data created a slightly pebbled surface to mimic a natural forest canopy. To eliminate small urban areas from the image, urban areas were extracted from the Land Cover data set, aggregated, placed on a layer mask in Photoshop, and a 1-pixel Median filter was applied. Alaskan glacier extents were extracted from the NA 1M Waterbodies. Inland water bodies were removed from the land cover with Photoshop s content aware fill tool. Manual touch-ups afterwards repaired discordant fill textures. All land cover received 0.7 application of Gaussian blur prior to merging it with the shaded relief.
Process Date
2013-01-01T00:00:00
Process Step
Description
Ocean areas were assigned a RGB value of (193,224,250) (blue) and non-U.S. land was assigned a value of (240,235,211) (tan).
Process Date
2013-01-01T00:00:00
Source
Title
100-Meter Resolution Land Cover of Alaska
Publication Date
2013-01-01
Originator
National Atlas of the United States
Description
Spatial and attribute information.
Source
Title
1:1,000,000-Scale Waterbodies of the United States
Publication Date
2012-07-01
Originator
National Atlas of the United States
Description
Spatial and attribute information.
Source
Title
100-Meter Resolution Elevation of Alaska
Publication Date
2012-12-01
Originator
National Atlas of the United States
Description
Spatial and attribute information.
Source
Title
100-Meter Resolution Satellite View of Alaska
Publication Date
2013-04-01
Originator
National Atlas of the United States
Description
Spatial and attribute information.
Source
Title
250-Meter Resolution MODIS Vegetation Continuous Fields forest canopy of Alaska
Publication Date
2011-01-01
Originator
University of Maryland, Global Land Cover Facility
Description
Spatial and attribute information.

Distribution Information

Format Name
GeoTIFF
Distributor
Stanford Geospatial Center
Online Access
http://purl.stanford.edu/nr598jf9933
Protocol
http
Name
nateaki0100a.tif
Function
download

Content Information

Content Type
image

Spatial Representation Information

Raster
Number of Dimensions
2
Row Count
20920
Column Count
49810
Cell Geometry Type
area
Corner Points
Point
-3327000.000000 346000.000000
Point
-3327000.000000 2438000.000000
Point
1654000.000000 2438000.000000
Point
1654000.000000 346000.000000
Center Point
-836500.000000 1392000.000000

Metadata Reference Information

Hierarchy Level
dataset
Metadata File Identifier
edu.stanford.purl:nr598jf9933
Parent Identifier
http://purl.stanford.edu/cv275yx9215.mods
Dataset URI
http://purl.stanford.edu/nr598jf9933
Metadata Date Stamp
2015-08-12
Metadata Standard Name
ISO 19139 Geographic Information - Metadata - Implementation Specification
Metadata Standard Version
2007
Character Set
utf8
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