NSIDC-0094
AVHRR Polar Pathfinder Twice-Daily 25 km EASE-Grid Composites
C. Fowler, J. Maslanik, T. Haran, T. Scambos, J. Key, and W. Emery.
AVHRR Polar Pathfinder Twice-Daily 25 km EASE-Grid Composites
2002-01-01
Boulder, Colorado USA
NSIDC: National Snow and Ice Data Center
http://nsidc.org/data/nsidc-0094.html
Investigator
Chuck
Fowler
Colorado Center for Astrodynamics Research
University of Colorado
Boulder
CO
80309-0431
Investigator
Jim
Maslanik
nsidc@kryos.colorado.edu
1 303 492-6199
1 303 492-2468
National Snow and Ice Data Center
CIRES, 449 UCB
University of Colorado
Boulder
CO
80309
Investigator
Terry
Haran
National Snow and Ice Data Center
CIRES, 449 UCB
University of Colorado
Boulder
CO
80309-0449
Investigator
Ted
Scambos
scambos@nsidc.org
University of Colorado
Cooperative Institute for Research in Environmental Science
National Snow and Ice Data Center
CIRES, 449 UCB
Boulder
CO
80309-0449
Investigator
Jeffrey
Key
Space Science and Engineering Center
University of Wisconsin at Madison
1225 W. Dayton St.
Madison
WI
53706
Investigator
William
Emery
Colorado Center for Astrodynamics Research
University of Colorado
Boulder
CO
80309-0431
Technical Contact
NSIDC
User Services
nsidc@nsidc.org
1 303 492-6199 x
1 303 492-2468 x
National Snow and Ice Data Center
CIRES, 449 UCB
University of Colorado
Boulder
CO
80309-0449
USA
EARTH SCIENCE
Atmosphere
Atmospheric Radiation
Albedo
EARTH SCIENCE
Atmosphere
Clouds
Cloud Amount/Frequency
EARTH SCIENCE
Cryosphere
Snow/Ice
Albedo
EARTH SCIENCE
Land Surface
Land Temperature
Land Surface Temperature
EARTH SCIENCE
Land Surface
Land Temperature
Skin Temperature
EARTH SCIENCE
Land Surface
Surface Radiative Properties
Albedo
EARTH SCIENCE
Land Surface
Surface Radiative Properties
Thermal Properties
EARTH SCIENCE
Spectral/Engineering
Infrared Wavelengths
Infrared Radiance
EARTH SCIENCE
Spectral/Engineering
Infrared Wavelengths
Thermal Infrared
EARTH SCIENCE
Spectral/Engineering
Platform Characteristics
Viewing Geometry
EARTH SCIENCE
Spectral/Engineering
Visible Wavelengths
Visible Radiance
EARTH SCIENCE
Terrestrial Hydrosphere
Snow/Ice
Albedo
Antarctic
Arctic
AVHRR
Cryosphere
DAAC
EOSDIS
NASA
NOAA
NSIDC
Pathfinder
Polar
Radiance
Remote Sensing
Satellite
AVHRR
Advanced Very High Resolution Radiometer
RADIOMETERS
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
1981-07-24
2000-12-31
in work
-90
-53.2
-180
180
48.4
90
-180
180
CONTINENT
ANTARCTICA
GEOGRAPHIC REGION
ARCTIC
GEOGRAPHIC REGION
POLAR
12:00:00
NOAA/NASA PATHFINDER
NOAA/NASA Pathfinder Program
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.
English
NSIDC_DAAC
NASA DAAC at the National Snow and Ice Data Center
http://nsidc.org/daac/index.html
Data Center Contact
NSIDC
User Services
nsidc@nsidc.org
1 303 492-6199
1 303 492-2468
National Snow and Ice Data Center
CIRES, 449 UCB
University of Colorado
Boulder
CO
80309-0449
USA
NSIDC
National Snow and Ice Data Center
http://nsidc.org
Data Center Contact
NSIDC
User Services
nsidc@nsidc.org
1 303 492-6199
1 303 492-2468
National Snow and Ice Data Center
CIRES, 449 UCB
University of Colorado
Boulder
CO
80309-0449
USA
FTP
127.3 KB
Binary
FTP
225.2 KB
Binary
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.
<font color="#FF0000">This data set is no longer available for use because of errors in the data. However, replacement data are expected by the end of 2012. If you need information pertaining to the data errors, please see the <a href="http://nsidc.org/data/docs/daac/nsidc0094_avhrr_25km_abstract.gd.html#errorsource">Error Sources Section of the guide documentation</a>. If you have further questions, contact NSIDC User Services by e-mail: <a href="mailto:nsidc@nsidc.org">nsidc@nsidc.org</a> or by telephone +1 303.492.6199.</font>
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.
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http://nsidc.org/data/avhrr/index.html
AVHRR Data at NSIDC
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http://nsidc.org/daac/pathfinder/index.html
Polar Pathfinders at NSIDC
VIEW RELATED INFORMATION
http://nsidc.org/data/ease/
All About EASE-Grid
USA/NASA
CEOS IDN DIF
9.7
2002-01-01
2012-08-14
Updated spatial coverage for the EDB per Donna's request.