DYCOMS-II Satellite:  DMSP SSM/I Rainfall Imagery (GIF)


1.0  General Information


The DMSP SSM/I Rainfall Imagery (GIF) is one of several 
satellite products collected as part of the Dynamics and 
Chemistry of Marine Stratocumulus Phase II:  Entrainment Studies 
(DYCOMS-II) project field catalog operated by the University 
Corporation for Atmospheric Research/Joint Office for Science Support 
(UCAR/JOSS; http://www.joss.ucar.edu/dycoms/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 1 - 30 July 2001 and 
cover the region from about 45 S to 45 N and 0 to 180 W.  The 
products were acquired from the NOAA/ETL
(http://www.etl.noaa.gov/satres/pacs_images.html)
All images are in GIF format.


2.0  Data Contact


Scot Loehrer (loehrer@ucar.edu)


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.
Currently we are receiving data from three SSM/I instruments,
including DMSP F11, F13, and F14, providing us with nearly
complete global daily coverage.

Ferriday global rainfall algorithm

This algorithm is based on a fairly simple combination of the
SSM/I channels utilizing all four SSM/I frequences as well as
dual polarization information. Different algorithms are utilized over
land and ocean with the ocean algorithm using both liquid water
emission and ice scattering information while the land algorithm
uses a simple ice scattering retrieval technique. The algorithm
was developed by James Ferriday (Ferriday and Avery 1994).


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_Rainfall.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_Rainfall is the name of the product


6.0  References


Ferriday, J. G. and S. K. Avery, 1994: Passive microwave remote
   sensing of rainfall with SSM/I: Algorithm development and
   implementation, J. Appl. Meteor., Vol 33, pp. 1587-1596.