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Global Change Master Directory (GCMD)
Alaska AVHRR Twice-Monthly Composites
Entry ID: AK_AVHRR


Summary
Abstract: The goal of the Alaska Advanced Very High Resolution Radiometer (AVHRR) project is to compile a time series data set of calibrated, georegistered daily observations and twice-monthly maximum normalized difference vegetation index (NDVI) composites for Alaska's annual growing season (April-October). This data set has applications for environmental monitoring and for assessing impacts of global climate change. An Alaska AVHRR data set is comprised of twice-monthly maximum NDVI composites of daily satellite observations. The NDVI composites contain 10 bands of information, including AVHRR channels 1-5, maximum NDVI, satellite zenith, solar zenith, and relative azimuth. The daily observations, bands 1-9, have been calibrated to reflectance, scaled to byte data, and geometrically registered to the Albers Equal-Area Conic map projection. The 10th band is a pointer to identify the date and scene ID of the source daily observation (scene) for each pixel.

The compositing process required each daily overpass to be registered to a common map projection to ensure that from day to day each 1-km pixel represented the exact same ground location. The Albers Equal-Area Conic map projection provides for equal area representation, which enables easy measurement of area throughout the data. Each daily observation for the growing season was registered to a base image using image-to-image correlation.

The NDVI data are calculated from the calibrated, geometrically registered daily observations. The NDVI value is the difference between near-infrared (AVHRR Channel 2) and visible (AVHRR Channel 1) reflectance values divided by total measured reflectance. A maximum NDVI compositing process was used on the daily observations. The NDVI is examined pixel by pixel for each observation during the compositing period to determine and retain the maximum value. Often when displaying data covering large areas, such as AVHRR data, it is beneficial to include an overlay of either familiar linework for reflectance or polygon data sets to derive statistical summaries of regions. All of the linework images represent lines in raster format as 1-km cells and the strata are represented as polygons registered to the AVHRR data. The linework and polygon data sets include international boundaries, Alaskan roads with the Trans-Alaska Pipeline, and a raster polygon mask of the State.

Related URL
Link: View Related Information
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Geographic Coverage
 N: 70.0 S: 51.0  E: -116.0  W: -179.0

Data Set Citation
Dataset Creator: U.S. Geological Survey
Dataset Title: Alaska AVHRR Twice-Monthly Composites
Dataset Release Date: 1990-01-01T00:00:00.000Z
Dataset Release Place: Sioux Falls, South Dakota,
USA

Dataset Publisher: U.S. Geological Survey
Version: Not provided
Data Presentation Form: Remote Sensing
Image


Temporal Coverage
Start Date: 1990-06-16


Location Keywords
CONTINENT > NORTH AMERICA
CONTINENT > NORTH AMERICA > UNITED STATES OF AMERICA > ALASKA > ALASKA


Science Keywords
BIOSPHERE >VEGETATION >VEGETATION COVER >NDVI    [Definition]
SPECTRAL/ENGINEERING >INFRARED WAVELENGTHS >INFRARED IMAGERY    [Definition]
SPECTRAL/ENGINEERING >VISIBLE WAVELENGTHS >VISIBLE IMAGERY    [Definition]


Platform
NOAA-11 >National Oceanic & Atmospheric Administration-11    [Information]
NOAA-14 >National Oceanic & Atmospheric Administration-14    [Information]
A340-600 >Airbus A340-600    [Information]
B-200 >Beechcraft King Air B-200    [Information]
NOAA-13 >National Oceanic & Atmospheric Administration-13    [Information]
NOAA-15 >National Oceanic & Atmospheric Administration-15    [Information]
NOAA-17 >National Oceanic & Atmospheric Administration-17    [Information]
NOAA-18 >National Oceanic & Atmospheric Administration-18    [Information]
NOAA-19 >National Oceanic & Atmospheric Administration-19    [Information]


Instrument
AVHRR >Advanced Very High Resolution Radiometer    [Information]


Access Constraints
None


Use Constraints
There is no guarantee of warranty concerning the accuracy of these data. Users should be aware that temporal changes may have occurred since the data was collected and that some parts of these data may no longer represent actual surface conditions. Users should not use these data for critical applications without a full awareness of their limitations. Acknowledgement of the originating agencies would be appreciated in products derived from these data. Any user who modifies the data set is obligated to describe the types of modifications they perform. User specifically agrees not to misrepresent the data set, nor to imply that changes made were approved or endorsed by the U.S. Geological Survey. Please refer to http://www.usgs.gov/privacy.html for the USGS disclaimer.


Keywords
ALASKA PIPELINE
AVHRR
COMPOSITE
USGS/EROS
HRPT
IMAGERY
LAC
NDVI
RADIANCE
RASTER
ROADS
SATELLITE
USGS


Data Set Progress
ACTIVE


Data Center
Earth Resources Observation and Science Center, U.S. Geological Survey, U.S. Department of the Interior    [Information]
Data Center URL: https://www.usgs.gov/centers/eros

Data Center Personnel
Name: EROS CENTER
Phone: 605-594-6151, 800-252-4547
Fax: 605-594-6589
Email: lta at usgs.gov
Contact Address:
LTA Customer Services
U.S. Geological Survey
EROS Center
47914 252nd Street
City: Sioux Falls
Province or State: SD
Postal Code: 57198-0001
Country: USA



Distribution
Distribution_Media: Digital Download
Fees: None


Personnel
EROS CENTER
Role: TECHNICAL CONTACT
Phone: 605-594-6151, 800-252-4547
Fax: 605-594-6589
Email: lta at usgs.gov
Contact Address:
LTA Customer Services
U.S. Geological Survey
EROS Center
47914 252nd Street
City: Sioux Falls
Province or State: SD
Postal Code: 57198-0001
Country: USA


INFORMATION SYSTEMS MANAGEMENT
Role: METADATA AUTHOR
Phone: 605-594-6594
Fax: 605-594-6589
Email: custserv at usgs.gov
Contact Address:
Information Systems Management
U.S. Geological Survey
EROS Data Center
47914 252nd Street
City: Sioux Falls
Province or State: SD
Postal Code: 57198-0001
Country: USA


Publications/References
Ailts, Blaine, Akkerman, Daniel, Quirk, Bruce, and Steinwand, Daniel (1990-01-01T00:00:00.000Z), LAS 5.0--an image processing system for research and production environments

Unknown (), ACSM/ASPRS Annual Convention, 50th/56th,, American Congress on Surveying and Mapping, American Society of Photogrammetry and Remote Sensing, 4, 1-12, Bethesda, Maryland

Holben, B.N. (1996-01-01T00:00:00.000Z), Characteristics of maximum-value composite images from temporal AVHRR Data, International Journal of Remote Sensing, 7, no. 11, 1,417-1,434.
Extended Metadata Properties
(Click to view more)

Creation and Review Dates
DIF Creation Date: 1970-01-01
Last DIF Revision Date: 2019-03-25



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