AVHRR Polar Pathfinder Twice-Daily 25 km EASE-Grid Composites
Entry ID: NSIDC-0094

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Summary
Abstract: This data set is no longer available because of errors in the data. See the http://nsidc.org/data/docs/daac/nsidc0094_avhrr_25km_abstract.gd.ht...>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 ... 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. View entire text
Related URL
Description: AVHRR Data at NSIDC
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Geographic Coverage
Spatial coordinates   
  N: 90.0   S: 48.4   E: 180.0   W: -180.0
  N: -53.2   S: -90.0   E: 180.0   W: -180.0

Data Set Citation
Dataset Originator/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
Temporal Coverage
Start Date: 1981-07-24
Stop Date: 2000-12-31
Data Resolution
Temporal Resolution: 12 hour
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 ... View entire text
Data Set Progress
IN WORK
Data Center
NSIDC Distributed Active Archive Center Supplemental Info
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 at 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
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Distribution
Distribution Media: FTP
Distribution Size: 127.3 KB
Distribution Format: Binary

Distribution Media: FTP
Distribution Size: 225.2 KB
Distribution Format: Binary
Personnel
Role: INVESTIGATOR
Contact Address:
Colorado Center for Astrodynamics Research
University of Colorado
City: Boulder
Province or State: CO
Postal Code: 80309-0431
Country: USA
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Publications/References
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 ... View entire text
Extended Metadata Properties
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Creation and Review Dates
DIF Creation Date: 2002-01-01
Last DIF Revision Date: 2014-07-16
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