ACE-ASIA Satellite:  DMSP SSM/I Derived Products, Water Vapor Imagery (GIF)


1.0  General Information


The DMSP SSM/I Water Vapor Imagery (GIF) is one of several satellite products collected as
part of the ACE-Asia project field catalog operated by the University Corporation for
Atmospheric Research/Joint Office for Science Support (UCAR/JOSS;
http://www.joss.ucar.edu/ace-asia/catalog/). The images were produced by the National
Oceanic and Atmospheric Administration (NOAA) Environmental Technology Laboratory
(ETL) from the Defense Meteorological Satellite Program (DMSP) Special Sensor
Microwave/Imager (SSM/I).  Images are available once per day.  The products cover the
period from 28 February 2001 to 4 May 2001 and cover the region from about 45S to 45N
and 0 to 180E.  The products were acquired from the NOAA/ETL
(http://www.etl.noaa.gov/satres/dmsp_game.html)  All images are in GIF format.


2.0  Data Contact

John Bates
NOAA/OAR/ETL
325 Broadway Street, Mailstop R/ET7
Boulder, CO  80305
Telephone: (303)497-6646
Email: John.J.Bates@noaa.gov


3.0  Product Information

The SSM/I data are provided courtesy of NOAA/NESDIS. SSM/I retrieved rainfall, cloud
liquid water, and integrated water  vapor products are computed daily over the region from
45S to 45N and 180E to 0W at a spatial resolution of 0.25 x 0.25 degrees. Data were 
received from three SSM/I instruments, including DMSP F11, F13, and F14.

Schluessel water vapor algorithm

Estimates of the total column integrated water vapor amount are estimated using 
information from the 22.235 GHz SSM/I channel (Schluessel and Emery 1990; Schulz et al 
1993; Bauer and Schluessel 1993), which is centered on a weak water vapor line. Integrated
water vapor is the simplest and most accurate product to retrieve from the SSM/I and is 
therefore very useful for quantitative comparisons with model results or other data sets. 


4.0  Quality Control Procedures


UCAR/JOSS conducted no quality checks on these data.


5.0  File Naming Convention


The file names are structured as follows:

dmsp.yyyymmdd.SSM-I_Water_Vapor.gif

Where dmsp is the type of satellite used
      yyyy is the four digit year
      mm is the two digit month
      dd is the two digit day
      SSM-I_Water_Vapor is the name of the product


6.0  References


Schluessel, P., and W. J. Emery, 1990: Atmospheric water vapour
   over oceans from SSM/I measurements, Int. J. of Remote 
   Sensing, Vol 11, pp. 753. 

Schulz, J., P. Schluessel, and H. Grassl, 1993: Water vapour in
   the atmospheric boundary layer over oceans from SSM/I
   measurements, Int. J. Rem. Sens., Vol 14, pp. 2773. 

Bauer, P. and P. Schluessel, 1993: Rainfall, total water, ice
   water, and water vapor over sea from polarized microwave
   simulations and special sensor microwave/imager data, J. 
   Geophys. Res., Vol 98, pp. 20,737.