TRMM Microwave Imager (TMI) Level 1 Raw and Calibrated Radiance Products (TRMM Product 1B11)Entry ID: GES_DISC_TRMM_1B11_V7
Abstract: The Tropical Rainfall Measuring Mission (TRMM) http://disc.gsfc.nasa.gov/precipitation/trmm_instr.shtml is a joint U.S.-Japan satellite mission to monitor tropical and subtropical precipitation and to estimate its associated latent heating.
The Level 1B product file (1B11) contains calibrated brightness temperatures and auxiliary geolocation information for each pixel in the scan. The structure ... of the Level 1B data file is based on the Wentz format for the SSM/I data. The Level 1B data are stored in the Hierarchical Data Format (HDF), which includes both core and product specific metadata applicable to the TMI measurements. A file contains a single orbit of data with a file size of about 14 MB (uncompressed). The HDF-EOS "swath" structure is used to accommodate the actual geophysical data arrays. As in the case of the Level 1A data, there are 16 files of TMI 1B11 data produced per day.
Antenna temperatures are derived from the Level 1A sensor counts by applying a linear relationship of the form: Tb = a + b * count. The resultant temperatures are corrected for cross-polarization and spill-over to produce the brightness temperatures found in the Level 1B product. However, no antenna beam pattern correction or ample-to-pixel averaging has been applied to these brightness temperatures.
In the Level 1B data, geolocation and channel data are written out for each pixel along the scan, whereas the time stamp, scan status (containing scan quality information), navigation, calibration coefficients, and satellite zenith angle are specified on a per-scan basis. There are, in general, 2991 scans along the orbit, with each scan consisting of 208 high resolution (85 GHz) pixels, and 104 low resolution pixels (all other channels). The scan width is about 760 km.
Spatial coverage is between 38 degrees North and 38 degrees South owing to the 35 degree inclination of the TRMM satellite. This orbit provides extensive coverage in the tropics and allows each location to be covered at a different local time each day, enabling the analysis of the diurnal cycle of precipitation.
Data Set Citation
Dataset Originator/Creator: NASA,JAXA, Tropical Rainfall Measuring Mission (TRMM)
Dataset Title: TRMM Microwave Imager (TMI) Level 1 Raw and Calibrated Radiance Product (TRMM Products 1B11)
Dataset Publisher: Goddard Space Flight Center Distributed Active Archive Center (GSFC DAAC)
Version: 7Online Resource: http://disc.gsfc.nasa.gov/datacollection/GES_DISC_TRMM_1B11_V7.shtml
Start Date: 1997-12-07
Latitude Resolution: 5-45 km
Longitude Resolution: 5-45 km
Horizontal Resolution Range: 10 km - < 50 km or approximately .09 degree - < .5 degree
Temporal Resolution: 16 orbits per day
Temporal Resolution Range: Daily - < Weekly
SPECTRAL/ENGINEERING > MICROWAVE > BRIGHTNESS TEMPERATURE
SPECTRAL/ENGINEERING > MICROWAVE > MICROWAVE RADIANCE
SPECTRAL/ENGINEERING > MICROWAVE > SENSOR COUNTS
SPECTRAL/ENGINEERING > PLATFORM CHARACTERISTICS > ATTITUDE CHARACTERISTICS
SPECTRAL/ENGINEERING > SENSOR CHARACTERISTICS > VIEWING GEOMETRY > SATELLITE LOCAL ZENITH ANGLE
Quality For the Level 1B TMI product, a Table structure (called Scan Status) has been included in the HDF file, containing entries on a scan-by-scan basis. These entries include a geolocation quality flag and a data quality flag for each channel, indicating the percentage of pixels along each scan with values within a pre-defined range.
Access Constraints None
Data Set Progress
Distribution Media: FTP
Distribution Size: up to 5771 files/year; file size ~14319KB
Distribution Format: HDF
Role: TECHNICAL CONTACT
Email: gsfc-help-disc at lists.nasa.gov
Goddard Earth Sciences Data and Information Services Center Code 610.2 NASA Goddard Space Flight Center
Province or State: MD
Postal Code: 20771
Role: DIF AUTHOR
Email: Zhong.Liu-1 at nasa.gov
NASA Goddard Space Flight Center Mailstop 610.2
Province or State: MD
Postal Code: 20771
File Specifications for TRMM Products: http://pps.gsfc.nasa.gov/Documents/filespec.TRMM.V7.pdf
Metadata for TRMM Products: http://pps.gsfc.nasa.gov/Documents/filespecMeta.TRMM.V7.pdf
TRMM V6 vs. V7 Major Data Format Changes: http://pps.gsfc.nasa.gov/Documents/formatChangesV7.pdf
Extended Metadata Properties
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Creation and Review Dates
DIF Creation Date: 2011-07-15
Last DIF Revision Date: 2014-09-11