Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Skip to content
  • Feedback

    • NOAA Climate Data Record (CDR) of AVHRR Polar Pathfinder (APP) Cryosphere, Version 2

    Metadata Updated: September 19, 2023

    This NOAA Climate Data Record (CDR) contains the AVHRR Polar Pathfinder (APP) product. APP is a fundamental CDR comprised of calibrated and navigated AVHRR channel data (reflectances and brightness temperatures), viewing and illumination geometry (sensor scan angle, solar zenith angle, and sun-sensor relative azimuth angle), Universal Coordinated Time (UTC) of the data acquisition, and a surface type mask. The data are twice daily composites of up to 23 orbits on a 5 km Equal-Area Scalable Earth (EASE)-Grid twice daily over both poles, the Arctic and Antarctic, from 1982 to the present. The daily APP composites are centered on local solar times of 14:00 (high sun, but could be nighttime for some polar areas in winter) and 04:00 for the Arctic or 02:00 for the Antarctic. The APP covers the north polar region (Arctic) from 48.4 degrees northward, and the south polar region (Antarctic) from -53.2 degrees southward. The update to version 2 of the APP FCDR was updated calibration coefficients for AVHRR GAC visible channels over the entire period.

    Access & Use Information

    License: No license information was provided. If this work was prepared by an officer or employee of the United States government as part of that person's official duties it is considered a U.S. Government Work.

    Downloads & Resources

    Dates

    Metadata Date August 10, 2023
    Metadata Created Date February 3, 2023
    Metadata Updated Date September 19, 2023
    Reference Date(s) 2019-05 (publication)
    Frequency Of Update daily

    Metadata Source

    Harvested from ncdc

    Other Data Resources

    Graphic Preview

    APP channel 1 reflectance

    Additional Metadata

    Resource Type Dataset
    Metadata Date August 10, 2023
    Metadata Created Date February 3, 2023
    Metadata Updated Date September 19, 2023
    Reference Date(s) 2019-05 (publication)
    Responsible Party NOAA Climate Data Record Program (CDRP) (Point of Contact)
    Contact Email
    Guid gov.noaa.ncdc:C01579
    Access Constraints Cite as: Key, Jeffrey; Liu, Yinghui; Wang, Xuanji; and NOAA CDR Program (2019):NOAA Climate Data Record (CDR) of AVHRR Polar Pathfinder (APP) Cryosphere, Version 2.0. NOAA National Centers for Environmental Information (NCEI). doi:10.25921/X2X1-JR34 [access date]., Distribution liability: NOAA and NCEI make no warranty, expressed or implied, regarding these data, nor does the fact of distribution constitute such a warranty. NOAA and NCEI cannot assume liability for any damages caused by any errors or omissions in these data. If appropriate, NCEI can only certify that the data it distributes are an authentic copy of the records that were accepted for inclusion in the NCEI archives., Use liability: NOAA and NCEI cannot provide any warranty as to the accuracy, reliability, or completeness of furnished data. Users assume responsibility to determine the usability of these data. The user is responsible for the results of any application of this data for other than its intended purpose.
    Bbox East Long 180.0
    Bbox North Lat 90.0
    Bbox South Lat -90.0
    Bbox West Long -180.0
    Coupled Resource
    Frequency Of Update daily
    Graphic Preview Description APP channel 1 reflectance
    Graphic Preview File https://www.ncei.noaa.gov/pub/data/metadata/images/C00940_browseimage.jpg
    Graphic Preview Type JPEG
    Harvest Object Id 72ac281e-a332-4b6b-9e31-2015c1143a74
    Harvest Source Id 2cb3ef77-1683-4c2a-9119-dc65e50917c6
    Harvest Source Title ncdc
    Licence For a complete description of use limitations for this CDR, see the Algorithm Theoretical Basis Document.
    Lineage This Climate Data Record (CDR) were produced by NOAA Center for Satellite Applications and Research (STAR) and University of Wisconsin and are archived at the NOAA National Centers for Environmental Information (NCEI).
    Metadata Language eng; USA
    Metadata Type geospatial
    Old Spatial {"type": "Polygon", "coordinates": [[[-180.0, -90.0], [180.0, -90.0], [180.0, 90.0], [-180.0, 90.0], [-180.0, -90.0]]]}
    Progress onGoing
    Spatial Data Service Type
    Spatial Reference System
    Spatial Harvester True
    Temporal Extent Begin 1982-01-01

    Didn't find what you're looking for? Suggest a dataset here.