Close

Service Interruption



AVHRR Polar Pathfinder Twice-Daily 25 km EASE-Grid Composites

View Catalog Page

Entry ID

NSIDC-0094

Summary

This data set is no longer available because of errors in the data. See the Error Sources section of the data set documentation for details. If you have further questions, please contact NSIDC User Services by e-mail at nsidc@nsidc.org or telephone at +1 303.492.6199.

The AVHRR Polar Pathfinder Twice-Daily 25 km EASE-Grid Composites are a collection of products for both poles, consisting of twice-daily gridded and calibrated satellite channel data and derived parameters. Data include five Advanced Very High Resolution Radiometer (AVHRR) channels, clear sky surface broadband albedo and skin temperature, average albedo and temperature, valid fraction file, solar zenith angle, satellite elevation angle, sun-satellite relative azimuth angle, surface type mask, cloud mask, cloud fraction files, and Universal Coordinated Time (UTC) of acquisition. The 25 km data are derived from the AVHRR Polar Pathfinder Twice-Daily 5 km EASE-Grid Composites, and extend poleward from 48.4 degrees north and 53.2 degrees south latitudes, spanning July 1981 through December 2000. Data are in 1-byte and 2-byte integer grid format and are available by FTP.

Note: NSIDC reccommends the use of the Extended AVHRR Polar Pathfinder (APP-x) Product instead of our AVHRR Polar Pathfinder Twice-Daily 25 km EASE-Grid Composites. The APP-x 25 km product has albedo and temperature calculations for all sky conditions. Cloud properties are modeled to estimate the albedo and temperature under the clouds. An improved cloud detection algorithm is also used in the APP-x product.

Geographic Coverage

 

Spatial Coordinates:
N: -53.2°     S: -90°     E: 180°     W: -180°    
N: 90°     S: 48.4°     E: 180°     W: -180°    

Data Set Citation

Dataset Creator: C. Fowler, J. Maslanik, T. Haran, T. Scambos, J. Key, and W. Emery.
Dataset Title: AVHRR Polar Pathfinder Twice-Daily 25 km EASE-Grid Composites
Dataset Release Date: 2002-01-01
Dataset Release Place: Boulder, Colorado USA
Dataset Publisher: NSIDC: National Snow and Ice Data Center
Online Resource: http://nsidc.org/data/nsidc-0094.html

Temporal Coverage

Start Date: 1981-07-24
Stop Date: 2000-12-31

Data Resolution

Temporal Resolution: 12:00:00

Location Keywords

  • CONTINENT ANTARCTICA
  • GEOGRAPHIC REGION ARCTIC
  • GEOGRAPHIC REGION POLAR

Science Keywords

  • Atmosphere Atmospheric Radiation Albedo
  • Atmosphere Clouds Cloud Amount/Frequency
  • Cryosphere Snow/Ice Albedo
  • Land Surface Land Temperature Land Surface Temperature
  • Land Surface Land Temperature Skin Temperature
  • Land Surface Surface Radiative Properties Albedo
  • Land Surface Surface Radiative Properties Thermal Properties
  • Spectral/Engineering Infrared Wavelengths Infrared Radiance
  • Spectral/Engineering Infrared Wavelengths Thermal Infrared
  • Spectral/Engineering Platform Characteristics Viewing Geometry
  • Spectral/Engineering Visible Wavelengths Visible Radiance
  • Terrestrial Hydrosphere Snow/Ice Albedo

Ancillary Keywords

  • Antarctic
  • Arctic
  • AVHRR
  • Cryosphere
  • DAAC
  • EOSDIS
  • NASA
  • NOAA
  • NSIDC
  • Pathfinder
  • Polar
  • Radiance
  • Remote Sensing
  • Satellite

Platform

  • NOAA-11 National Oceanic & Atmospheric Administration-11
  • NOAA-14 National Oceanic & Atmospheric Administration-14
  • NOAA-7 National Oceanic & Atmospheric Administration-7
  • NOAA-9 National Oceanic & Atmospheric Administration-9

Instrument

  • AVHRR Advanced Very High Resolution Radiometer
  • RADIOMETERS

Project

  • NOAA/NASA PATHFINDER NOAA/NASA Pathfinder Program

Quality

Channel data are accurate to within approximately +/- 0.2 percent based on sensor noise level of 0.4 data number (DN). Temperatures are accurate to within approximately 2 degrees Kelvin. Relative albedos in adjacent grid cells are accurate to within approximately 5 percent. However, absolute albedo values are approximate. Accuracies for the products are difficult to determine, given the limited nature of existing case studies. Also, conditions vary substantially across the large product domains and over time. Plans are being developed to further define product accuracies for snow-covered areas, sea ice, and ice sheets. Based on studies to date, accuracies in general are approximately +/- 2 degrees Kelvin for AVHRR-derived skin temperatures and +/- 0.05 degrees for surface albedo. Much of this error is likely due to uncertainties in the performance of the cloud detection methods. For clear sky conditions, accuracies for albedo and temperature products are expected to be in the range noted in the Barrow test, with temperatures accurate to +/- 0.5 degrees Celsius. Data and related information will be updated as appropriate. Additional comparisons with in-situ measurements of albedo and temperature are planned. See also Maslanik et al. (2000) for other accuracy discussions relative to SHEBA data.

Data Set Progress

in work

Data Center

NASA DAAC at the National Snow and Ice Data Center
Data Center URL: http://nsidc.org/daac/index.html

Data Center Personnel

Name: NSIDC User Services
Phone: 1 303 492-6199
Fax: 1 303 492-2468
Email: nsidc@nsidc.org
Contact Address:

  • National Snow and Ice Data Center
  • CIRES, 449 UCB
  • University of Colorado

City: Boulder
Province or State: CO
Postal Code: 80309-0449
Country: USA

National Snow and Ice Data Center
Data Center URL: http://nsidc.org

Data Center Personnel

Name: NSIDC User Services
Phone: 1 303 492-6199
Fax: 1 303 492-2468
Email: nsidc@nsidc.org
Contact Address:

  • National Snow and Ice Data Center
  • CIRES, 449 UCB
  • University of Colorado

City: Boulder
Province or State: CO
Postal Code: 80309-0449
Country: USA

Distribution

Distribution Media: FTP
Distribution Size: 127.3 KB
Distribution Format: Binary

Distribution Media: FTP
Distribution Size: 225.2 KB
Distribution Format: Binary

Personnel

Chuck Fowler
Role: INVESTIGATOR
Contact Address:

  • Colorado Center for Astrodynamics Research
  • University of Colorado

City: Boulder
Province or State: CO
Postal Code: 80309-0431

Jim Maslanik
Role: INVESTIGATOR
Phone: 1 303 492-6199
Fax: 1 303 492-2468
Email: nsidc@kryos.colorado.edu
Contact Address:

  • National Snow and Ice Data Center
  • CIRES, 449 UCB
  • University of Colorado

City: Boulder
Province or State: CO
Postal Code: 80309

Terry Haran
Role: INVESTIGATOR
Contact Address:

  • National Snow and Ice Data Center
  • CIRES, 449 UCB
  • University of Colorado

City: Boulder
Province or State: CO
Postal Code: 80309-0449

Ted Scambos
Role: INVESTIGATOR
Email: scambos@nsidc.org
Contact Address:

  • University of Colorado
  • Cooperative Institute for Research in Environmental Science
  • National Snow and Ice Data Center
  • CIRES, 449 UCB

City: Boulder
Province or State: CO
Postal Code: 80309-0449

Jeffrey Key
Role: INVESTIGATOR
Contact Address:

  • Space Science and Engineering Center
  • University of Wisconsin at Madison
  • 1225 W. Dayton St.

City: Madison
Province or State: WI
Postal Code: 53706

William Emery
Role: INVESTIGATOR
Contact Address:

  • Colorado Center for Astrodynamics Research
  • University of Colorado

City: Boulder
Province or State: CO
Postal Code: 80309-0431

NSIDC User Services
Role: TECHNICAL CONTACT
Phone: 1 303 492-6199 x
Fax: 1 303 492-2468 x
Email: nsidc@nsidc.org
Contact Address:

  • National Snow and Ice Data Center
  • CIRES, 449 UCB
  • University of Colorado

City: Boulder
Province or State: CO
Postal Code: 80309-0449
Country: USA

Related URL

VIEW PROJECT HOME PAGE
AVHRR Data at NSIDC

VIEW PROJECT HOME PAGE
Polar Pathfinders at NSIDC

VIEW RELATED INFORMATION
All About EASE-Grid

Reference

Key, J. 1999. The cloud and surface parameter retrieval (CASPR) system for polar AVHRR. Cooperative Institute for Meteorological Satellite Studies, University of Wisconsin, Madison.

Key, J., J. Collins, C. Fowler, and R.S. Stone. 1997. High-latitude surface temperature estimates from thermal satellite data. Remote Sensing of the Environment 61:302-309.

Kidwell, K.D. 1995. NOAA Polar Orbiter Data User's Guide, U.S. Dept. of Commerce, National Oceanic and Atmospheric Administration, NESDIS.

Maslanik, J., C. Fowler, J. Key, T. Scambos, T. Hutchinson, and W. Emery, 1998. AVHRR-based Polar Pathfinder products for modeling applications. Annals of Glaciology 25:388-392.

Rao, C.R.N. and J. Chen. 1999. Revised post-launch calibration of channels 1 and 2 of the Advanced Very High Resolution Radiometer on board the NOAA-14 spacecraft. http://noaasis.noaa.gov/NOAASIS/ml/aboutn14vis.html.

Schweiger, A., C. Fowler, J. Key, J. Maslanik, J. Francis, R. Armstrong, M.J. Brodzik, T. Scambos, T. Haran, M. Ortmeyer, S. Khalsa, D. Rothrock, and R. Weaver. 1999. P-Cube: A multisensor data set for polar climate research. Proceedings on the 5th Conference on Polar Meteorology and Oceanography, American Meteorological Society, Dallas, TX, 15-20 Jan., 136-141.

Metadata Name and Version

Metadata Name: CEOS IDN DIF
Metadata Version: 9.7

Creation and Review Dates

DIF Creation Date: 2002-01-01
Last DIF Revision Date: 2013-11-26

Metadata Views

DIF Text-Only

Directory Interchange Format (DIF) in plain text

DIF XML

Directory Interchange Format (DIF) in Extensible Markup Language (XML)

FGDC HTML

U.S. Federal Geographic Data Committee (FGDC) Content Standard for Digital Geospatial Metadata (CSDGM)

ISO HTML

International Organization for Standardization (ISO) 19115:2003 Geographic Information Metadata

Back to Top