AK_AVHRR_Not provided

Alaska AVHRR Twice-Monthly Composites

Version Not provided eng
  • 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.

Data Identification Fields:

Toggle Data Identification Fields
    Processing Level

    Not provided

    Quality
    Collection Progress

    Active

    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.
    Access Constraints

    None

    Publication References
    • LAS 5.0--an image processing system for research and production environments
      1990-01-01

      Author(s) Ailts, Blaine, Akkerman, Daniel, Quirk, Bruce, and Steinwand, Daniel

    • ACSM/ASPRS Annual Convention, 50th/56th,

      Author(s) Unknown

      American Congress on Surveying and Mapping, American Society of Photogrammetry and Remote Sensing

      Vol: 4

      Pages: 1-12

    • Characteristics of maximum-value composite images from temporal AVHRR Data
      1996-01-01

      Author(s) Holben, B.N.

      International Journal of Remote Sensing

      Vol: 7

      Iss: no. 11

      Pages: 1,417-1,434.

Related URLs
    Science Keywords
    • EARTH SCIENCE
    • BIOSPHERE
    • VEGETATION
    • VEGETATION COVER
    • NDVI
    • EARTH SCIENCE
    • SPECTRAL/ENGINEERING
    • INFRARED WAVELENGTHS
    • INFRARED IMAGERY
    • EARTH SCIENCE
    • SPECTRAL/ENGINEERING
    • VISIBLE WAVELENGTHS
    • VISIBLE IMAGERY
Other Descriptive Keywords
Toggle Other Descriptive Keywords Fields
Ancillary Keywords
  • ALASKA PIPELINE
  • AVHRR
  • COMPOSITE
  • USGS/EROS
  • HRPT
  • IMAGERY
  • LAC
  • NDVI
  • RADIANCE
  • RASTER
  • ROADS
  • SATELLITE
  • USGS
ISO Topic Categories
  • BIOTA
  • IMAGERY/BASE MAPS/EARTH COVER
Additional Attributes
  • metadata.uuid
    STRING
    Not provided
    Resolution Range Begin Range End Unit of Measure Accuracy

  • metadata.extraction_date
    STRING
    Not provided
    Resolution Range Begin Range End Unit of Measure Accuracy

  • metadata.keyword_version
    FLOAT
    Not provided
    Resolution Range Begin Range End Unit of Measure Accuracy

Acquisition Information Fields:

Toggle Acquisition Information Fields
Platforms
  • Not provided
    Instruments
    • AVHRR
  • NOAA-11
    Instruments
  • NOAA-14
    Instruments
  • A340-600
    Instruments
  • B-200
    Instruments
  • NOAA-13
    Instruments
  • NOAA-15
    Instruments
  • NOAA-17
    Instruments
  • NOAA-18
    Instruments
  • NOAA-19
    Instruments

Temporal Information Fields:

Toggle Temporal Information Fields

Spatial Information Fields:

Toggle Spatial Information Fields
    Coverage Type Zone Identifier Geometry Granule Representation
    HORIZONTAL CARTESIAN NO_SPATIAL
Location Keywords
    • CONTINENT
    • NORTH AMERICA
    • CONTINENT
    • NORTH AMERICA
    • UNITED STATES OF AMERICA
    • ALASKA
    • ALASKA

Data Centers

Toggle Data Centers
  • DOI/USGS/EROS
    Multiple Roles

    ARCHIVER

    DISTRIBUTOR

    Earth Resources Observation and Science Center, U.S. Geological Survey, U.S. Department of the Interior

    This data center does not have any addresses listed.

    This data center does not have any contact mechanisms listed.

Data Contacts

Toggle Data Contacts
  • Technical Contact
    EROS CENTER

    LTA Customer Services
    U.S. Geological Survey
    EROS Center
    Sioux Falls, SD 57198-0001

    • Email
    • 605-594-6589
    • 605-594-6151, 800-252-4547
  • Metadata Author
    INFORMATION SYSTEMS MANAGEMENT

    Information Systems Management
    U.S. Geological Survey
    EROS Data Center
    Sioux Falls, SD 57198-0001

    • Email
    • 605-594-6589
    • 605-594-6594
  • Data Center Contact
    EROS CENTER

    DOI/USGS/EROS

    LTA Customer Services
    U.S. Geological Survey
    EROS Center
    Sioux Falls, SD 57198-0001

    • Email
    • 605-594-6589
    • 605-594-6151, 800-252-4547

Collection Citations Fields:

Toggle Collection Citations Fields
    Collection Citations
    • Alaska AVHRR Twice-Monthly Composites

      Created by:

      Published by: U.S. Geological Survey

      Released: