SSM/I EASE Grid Data Products for SGP97
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| SSMI Footprint Data | SSMI Ease-Grid products |  SSM/I page |
The Data
SSM/I EASE Grid Data Parameters Brightness temperatures Units Degrees Kelvin Temporal Coverage 1997 day 169 (Jun 18) - 1997 day 201 (Jul 20) Temporal Resolution Spatial Coverage 34.5-37N, 97.25-98.5W [lat/lon subset box used by Tom Jackson/Ann Hsu for SSM/I footprint (ungridded) data]. (See table below) Spatial Resolution 69x43 km Data Format
Strip #Files/strip #File@type Channels One strip=segment of an orbit over the area of interest 8 5 channel files
1 time file
1 *.extract.* file
1 *.tdrextract.* file19v
19h
22v
37v
37h*Processing notes
- To remove any edge effects associated w/EASE-Grid resampling, the box was extended to to 33-38 N, 96-100 W.
- EASE-Grid coordinates of box corners & TMRS2 at ARM Central Facility: (cylindrical projection)
Row Col Lat Lon NW corner 112 307 38 -100 NE corner 112 322 38 -96 SW corner 133 307 33 -100 SE corner 133 322 33 -96 CF(TMRS2) 117 316 36.6063 -97.4883
- No pre-EASE-Grid pixel extraction was performed. (*.tdrextract.* files are empty)
- No special post-EASE-Grid pixel extraction was performed. (*.extract.* files contain ALL pixels within the subset box)
- SPATIAL RESOLUTION: all processed channels have the same footprint AREA as the 19V channel (69x43 km).
- GRID POINT SPACING: 25 km Cylindrical Projection EASE-Grid [1].
- SSM/I CHANNELS PROCESSED: 19V,19H,22V,37V,37H 85 GHz data are not processed into EASE-Grid by the current Custom EASE-Grid Processor [3].
- DMSP SATELLITES PROCESSED: F-13 and F-14. F-10 data was NOT gridded because the effects of its eccentric orbit on the resampling algorithm were not known.
The Files
Format
File Formats Group File type Format Headers/
footers#Files Compression File size Storage required Compressed Uncompressed Compressed Channel binary EASE Grid (2-D arrays) None 644 GZIP
(~99%)~3.5KB ~1.5MB 3.2MB *.tim.* binary EASE Grid (2-D arrays) none 129 ~1KB ~.8MB *.extract.* ascii
11-column tables
Columns from left:sat# yyjjj.jjj lat long row col 19v 19h 22v 37v 37h None 129 NA NA 3.4KB *.tdrextract.* ascii Empty NA 127 NA NA NA Name and Directory Information
SoftwareNaming Convention for Data and Image Files
The SSM/I EASE Grid file names are of the formxxxxxx.sss.Mlyydddq.ffp.stripN.gzwhere
xxxxxx = unique identifier;
sss = 'F13' or 'F14' (which SSM/I); 'Ml' indicates cylindrical low-res (25km) EASE-Grid;
yyddd = year and Julian Day;
q = 'A' for ascending or 'D' for descending pass;
ffp = channel or 'tim' (time file) or 'tdrextract' or 'extract';
N = '1', '2', '3', etc.;
'.gz' suffix indicates gzip compressed.
Freeware IDL tools by NSIDC for displaying and working with these data files are available[4].
Data Access and Contacts
FTP SiteThe SSM/I EASE Grid data is in the following GES DISC ftp site:
Points of Contact
- Dr. Edward J. Kim
- Microwave Sensors & Hydrological Sciences Branches
- Code 975 (Bldg 33, Rm A426)
- NASA Goddard Space Flight Center
- Greenbelt, MD 20771 USA
E-mail: Edward.J.Kim.1@gsfc.nasa.gov
Voice: 301-614-5653
- For more information on SSM/I EASE Grid data from the GES DISC, contact:
- Hydrology Data Support Team
- Goddard Earth Sciences
Data and Information Serveices Center (GES DISC)- Code 610.2
- NASA Goddard Space Flight Center
- Greenbelt, Maryland 20771
E-mail: hydrology-disc@listserv.gsfc.nasa.gov
Voice: 301-614-5165
Fax: 301-614-5268
References
[1] Brodzik, M.J., ``The NSIDC EASE-Grid Map Projection Parameters and Grid Definitions,'' Unpublished report, National Snow and Ice Data Center, Boulder, CO, 1997. Available at http://www-nsidc.colorado.edu/NASA/GUIDE/EASE/ease_maps_info.html
[2] O'Kray, C., ``TDR to EASE-Grid Conversion Process Documentation,'' Technical Report RL-960, Radiation Laboratory, University of Michigan, Ann Arbor, MI, 1998. Available at http://www.eecs.umich.edu/grs/ under "Satellite Data".
[3] Kim, E.J., et al, ``A Custom EASE-Grid SSM/I Processing System,'' Int'l Geoscience and Remote Sensing Symposium Proc., vol. 2, Seattle, WA, July, 1998. Available at http://www.eecs.umich.edu/grs/ under "Satellite Data".
[4] NOAA/NASA Pathfinder Program EASE-Grid DMSP SSM/I Brightness Temperatures on CD-ROM, National Snow and Ice Data Center, Boulder, CO, 1994--1998. The IDL tools are available for FTP from http://www.eecs.umich.edu/grs/ under "Satellite Data" as part of the download package.
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Last update:Fri Jan 15 14:23:52 EST 1999 Page Author: Hydrology Data Support Team -- hydrology-disc@listserv.gsfc.nasa.gov Web Curator: -- Stephen W Berrick NASA official: Steven Kempler, DAAC Manager -- Steven.J.Kempler@nasa.gov |