Entry_ID: NSIDC-0265
Entry_Title: NASA SCP Arctic and Antarctic Ice Extent from QuikSCAT, 1999-2009
Group: Data_Set_Citation
   Dataset_Creator: Long, D. G. 
   Dataset_Title: NASA SCP Arctic and Antarctic Ice Extent from QuikSCAT, 1999-2009
   Dataset_Release_Date: 2013-04-03
   Dataset_Release_Place: Boulder, Colorado USA
   Dataset_Publisher: NSIDC DAAC: NASA DAAC at the National Snow and Ice Data Center
   Version: 2
   Online_Resource: http://nsidc.org/data/nsidc-0265.html
End_Group
Group: Personnel
   Role: Technical Contact
   First_Name: NSIDC
   Last_Name: User Services
   Email: nsidc@nsidc.org
   Phone: 1 303 492-6199 x
   Fax: 1 303  492-2468 x
   Group: Contact_Address
      Address: National Snow and Ice Data Center
      Address: CIRES, 449 UCB
      Address: University of Colorado
      City: Boulder
      Province_or_State: CO
      Postal_Code: 80309-0449
      Country: USA
   End_Group
End_Group
Group: Personnel
   Role: Investigator
   First_Name: David
   Middle_Name: G.
   Last_Name: Long
   Email: long@et.byu.edu
   Group: Contact_Address
      Address: Brigham Young University
      Address: Microwave Earth Remote Sensing (MERS) Laboratory
      Address: 459 Clyde Building
      City: Provo
      Province_or_State: UT
      Postal_Code: 84602
      Country: USA
   End_Group
End_Group
Group: Parameters
   Category: EARTH SCIENCE
   Topic: Cryosphere
   Term: Sea Ice
   Variable_Level_1: Ice Extent
End_Group
Group: Parameters
   Category: EARTH SCIENCE
   Topic: Cryosphere
   Term: Sea Ice
   Variable_Level_1: Ice Extent
End_Group
Group: Parameters
   Category: EARTH SCIENCE
   Topic: Oceans
   Term: Sea Ice
   Variable_Level_1: Ice Extent
End_Group
Group: Parameters
   Category: EARTH SCIENCE
   Topic: Oceans
   Term: Sea Ice
   Variable_Level_1: Ice Extent
End_Group
ISO_Topic_Category: Climatology/Meteorology/Atmosphere
Keyword: DAAC
Keyword: ice sheets
Keyword: Ku- band radar
Keyword: LANDFORMS
Keyword: NASA
Keyword: NSIDC DAAC
Keyword: NSIDC > National Snow and Ice Data Center
Keyword: QuikSCAT
Keyword: Satellite Radar Data
Keyword: Scatterometer
Keyword: SCP > Scatterometer Climate Record Pathfinder
Keyword: Sea Ice Extent
Sensor_Name: SCATTEROMETERS
Sensor_Name: SEAWINDS > SeaWinds
Source_Name: QUIKSCAT > Quick Recovery Scatterometer
Source_Name: SATELLITES
Group: Temporal_Coverage
   Start_Date: 1999-07-19
   Stop_Date: 2009-12-31
End_Group
Data_Set_Progress: complete
Group: Spatial_Coverage
   Southernmost_Latitude: -90
   Northernmost_Latitude: -52
   Westernmost_Longitude: -180
   Easternmost_Longitude: 180
End_Group
Group: Spatial_Coverage
   Southernmost_Latitude: 60
   Northernmost_Latitude: 90
   Westernmost_Longitude: -180
   Easternmost_Longitude: 180
End_Group
Group: Location
   Location_Category: CONTINENT
   Location_Type: ANTARCTICA
End_Group
Group: Location
   Location_Category: GEOGRAPHIC REGION
   Location_Type: ARCTIC
End_Group
Group: Data_Resolution
   Latitude_Resolution: 4.45 km
   Longitude_Resolution: 4.45 km
   Temporal_Resolution: 1 day
End_Group
Group: Data_Resolution
   Latitude_Resolution: 2.225 km
   Longitude_Resolution: 2.225 km
   Temporal_Resolution: 1 day
End_Group
Project: SCP > NASA Scatterometer Climate Record Pathfinder
Group: Quality

   Sea ice extent images were manually checked for spatial and temporal 
   consistency. NSIDC noticed some inconsistencies in the ice extents from 
   QuikSCAT. Slice images appear much noisier than egg images in the Arctic, 
   particularly in 2003 and 2004.

   Antarctic ice extents should match well between QuikSCAT and Special Sensor 
   Microwave/Imager (SSM/I) using a 30% ice concentration threshold, but a 
   preliminary analysis shows they match well even with a 15% threshold. In the 
   Arctic, SSM/I shows much greater winter ice extents compared to QuikSCAT.

   The differences in arctic ice extent between SSM/I and QuikSCAT may relate to 
   the physical properties of the ice, in the sense that QuikSCAT does not 'see' 
   the first-year ice as readily as it sees the more highly scattering multiyear 
   ice. In the Antarctic -- where pancake ice, frazil ice formation, and refrozen 
   snow slush at the snow/ice interface are prevalent -- scattering is sufficient 
   enough to yield similar extent results between SSM/I and QuikSCAT 
   scatterometer data.

   This data set is unchanged from the original format. An improved version of 
   this data set will be available in the future.

End_Group
Group: Use_Constraints

   Any use of images or data should include the following acknowledgement and 
   citations: 'Ice extent images (or maps) are courtesy of David G. Long at 
   Brigham Young  University, generated by the Scatterometer Climate Record 
   Pathfinder project from data obtained from the PO.DAAC.'

   Early, D.S., and and D.G. Long. 2001. Image reconstruction and enhanced  
   resolution imaging from irregular samples. IEEE Transactions on Geoscience and 
    Remote Sensing 39(2): 291-302. Long, D.G. 2004. NASA SCP arctic and antarctic 
   ice extent from QuikSCAT, 1999-2004. Boulder, CO, USA: National Snow and Ice 
   Data Center. Digital media. Remund, Q.P., and D.G. Long. 1999. Sea ice extent 
   mapping using Ku-band scatterometer data. Journal of Geophysical Research 
   104(C5): 11515-11527. Please send reprints of papers, reports, or 
   presentations using these data to NSIDC User Services, the Physical 
   Oceanography Distributed Active Archive Center (PO.DAAC) and David Long.

End_Group
Data_Set_Language: English
Originating_Center: NSIDC_DAAC
Group: Data_Center
   Data_Center_Name: NASA DAAC > NASA DAAC at the National Snow and Ice Data Center
   Data_Center_URL: http://nsidc.org/daac/index.html
   Group: Personnel
      Role: Data Center Contact
      First_Name: NSIDC
      Last_Name: User Services
      Email: nsidc@nsidc.org
      Phone: 1 303 492-6199 
      Fax: 1 303  492-2468 
      Group: Contact_Address
         Address: National Snow and Ice Data Center
         Address: CIRES, 449 UCB
         Address: University of Colorado
         City: Boulder
         Province_or_State: CO
         Postal_Code: 80309-0449
         Country: USA
      End_Group
   End_Group
End_Group
Group: Data_Center
   Data_Center_Name: NSIDC > National Snow and Ice Data Center
   Data_Center_URL: http://nsidc.org
   Group: Personnel
      Role: Data Center Contact
      First_Name: NSIDC
      Last_Name: User Services
      Email: nsidc@nsidc.org
      Phone: 1 303 492-6199 
      Fax: 1 303  492-2468 
      Group: Contact_Address
         Address: National Snow and Ice Data Center
         Address: CIRES, 449 UCB
         Address: University of Colorado
         City: Boulder
         Province_or_State: CO
         Postal_Code: 80309-0449
         Country: USA
      End_Group
   End_Group
End_Group
Group: Distribution
   Distribution_Media: FTP
   Distribution_Size: 12 to 17 MB
   Distribution_Format: Binary
End_Group
Group: Distribution
   Distribution_Media: FTP
   Distribution_Size: 7 to 10 MB
   Distribution_Format: GIF
End_Group
Group: Distribution
   Distribution_Media: FTP
   Distribution_Size: 4 to 5 MB
   Distribution_Format: ASCII Text (.txt)
End_Group
Group: Reference

   Early, D.S., and and D.G. Long. 2001. Image Reconstruction and Enhanced 
   Resolution Imaging from Irregular Samples. IEEE Transactions on Geoscience and 
   Remote Sensing 39(2): 291-302. 

   Jet Propulsion Laboratory. 2001. QuikSCAT Science Data Product User's Manual, 
   Version 2.2.View PDF (346 KB).

   Kramer, H.J. 1994. Observation of the Earth and its Environment. New York: 
   Springer-Verlag. Long, D. 2000. Standard BYU QuikScat/Seawinds Land/Ice Image 
   Products, Revision 2.0. Unpublished report. Provo, UT: Microwave Earth Remote 
   Sensing Laboratory, Brigham Young University. View PDF (1.2 MB).

   Long, D.G., and M.R. Drinkwater. 2000. Azimuth Variation in Microwave 
   Scatterometer and Radiometer Data over Antarctica. IEEE Transactions on 
   Geoscience and Remote Sensing 38(4): 1857-1870. 

   Long, D.G., and M.R. Drinkwater. 1999. Cryosphere Applications of NSCAT Data. 
   IEEE Transactions Geoscience and Remote Sensing 37(3): 1671-1684.

   Long, D.G., P.J. Hardin, and P.T. Whiting. 1993. Resolution Enhancement of 
   Spaceborne Scatterometer Data. IEEE Transactions on Geosciences and Remote 
   Sensing 32(3): 700-715.

   Remund, Q.P., and D.G. Long. 2000. Iterative Estimation of Antarctic Sea Ice 
   Extent Using SeaWinds Data. Proceedings of the International Geoscience and 
   Remote Sensing Symposium, Honolulu, HI, 24-28 July 2000, pp. 491-493. Remund, 
   Q.P., and D.G. Long. 1999. 

   Sea Ice Extent Mapping Using Ku-band Scatterometer Data. Journal of 
   Geophysical Research 104(C5): 11515-11527. Remund, Q.P., and D.G. Long. 1998.

   Sea Ice Mapping Algorithm for QuikSCAT and Seawinds. Proceedings of the 
   International Geoscience and Remote Sensing Symposium, Seattle, WA, 6-10 July 
   1998, pp. 1686-1688.

   Remund, Q.P., and D.G. Long. 1997. Automated Antarctic Ice Edge Detection 
   Using NSCAT Data. Proceedings of the International Geoscience and Remote 
   Sensing Symposium, Singapore, 4-8 August 1997, pp. 1841-1843.

   Scatterometer Climate Record Pathfinder (SCP). 'General BYU SIR file naming 
   scheme.' 2004. http://www.scp.byu.edu/docs/SIRfilename.html. Accessed January 
   2005. Scatterometer Climate Record Pathfinder (SCP). 'NSCAT-Derived Antarctic 
   Sea-Ice Extent.' 2004. 
   http://www.scp.byu.edu/data/NSCAT/iceproduct/doc/sea-ice-extent. Accessed 
   January 2005.

   Scatterometer Climate Record Pathfinder (SCP). 'QuikSCAT Ice Extent Products.' 
   2004. http://www.scp.byu.edu/data/Quikscat/Ice/Quikscat_ice.html. Accessed 
   January 2005.

   Spencer, M.W., C. Wu, and D.G. Long. 2000. Improved Resolution Backscatter 
   Measurements with the SeaWinds Pencil-beam Scatterometer. IEEE Transactions on 
   Geoscience and Remote Sensing 38(1): 89-104.

End_Group
Group: Summary

   This data set provides sea ice extent for the Arctic (60-90 degrees North) and 
   Antarctic (52-90 degrees South) in Scatterometer Image Reconstruction (SIR) 
   binary image format, along with ASCII text files containing latitude and 
   longitude coordinates along the sea ice edge, and browse images of SIR files 
   in Graphics Interchange Format (GIF) format. Ancillary products include 
   daily-averaged total sea ice extent in ASCII format. Estimates of sea ice 
   extent were produced from daily-averaged QuikSCAT sigma-0 measurements and 
   extend from 19 July 1999 to 31 December 2009.

   QuikSCAT obtains 12 individual radar normalized backscatter (sigma-0) 
   measurements, called slices, for each footprint as it scans over a 1800 km 
   wide swath. Slices are typically 4 to 6 km long by 20 km wide. The summed 
   measurements of the slices are called egg measurements. The effective 
   resolution and shape of each egg measurement is approximately 20 by 30 km, 
   depending on the antenna beam and instrument mode. This data set contains both 
   slice and egg images for each day.

   The Microwave Earth Remote Sensing (MERS) group at Brigham Young University 
   (BYU) developed a SIR-with-filtering (SIRF) algorithm that combines forward- 
   and aft-looking sigma-0 measurements to produce enhanced-resolution 
   backscatter images over various azimuth angles. The polarization ratio, 
   incidence angle dependence, and the sigma-0 estimate error standard deviation 
   were used to discriminate between sea ice and ocean. Sea ice extent was 
   estimated for both slice and egg images. The nominal pixel resolution of the 
   slice images is 2.225 km with an estimated effective resolution of 
   approximately 4 km. Egg images have a nominal pixel resolution of 4.45 km with 
   an estimated effective resolution of approximately 8 to 10 km.

   Data and browse images are available via FTP, along with C, Fortran, and 
   Interactive Data Language (IDL) tools to read and display the SIR images.

End_Group
Group: Related_URL
   Group: URL_Content_Type
      Type: VIEW PROJECT HOME PAGE
   End_Group
   URL: http://www.scp.byu.edu/
   Description: NASA Scatterometer Climate Record Pathfinder (SCP)
End_Group
Metadata_Name: CEOS IDN DIF
Metadata_Version: 9.7
DIF_Creation_Date: 2013-04-03
Last_DIF_Revision_Date: 2013-06-24
DIF_Revision_History:  updated publisher