Remote Sensing Systems
readme for the
Version-01b
Passive Microwave Water Cycle (PMWC) Dataset
produced for the
NASA Energy and Water Cycle Study (NEWS).

We have developed reading routines and a verification
file for the SSM/I binary data files to assist you
in using these data.  The read routines have been
tested and work correctly within our PC environment.
We do not guarantee that they work perfectly in a different
environment with different compilers.

Reading routines for FORTRAN, IDL, and Matlab are available
in the "support" folder.

Read routines for C and GrADS are not available at this time.

The data files contain six 0.25-degree (1440x720) maps:
1. Water Vapor Transport Speed
2. Water Vapor Transport Direction
3. Water Vapor Transport Divergence
4. Evaporation
5. Precipitation
6. Water Vapor
The maps are one byte with valid geophysical data falling
between 0 and 250 with special values for:
252 = Sea Ice
254 = Insufficient Data
255 = Land
The scale factors and offsets are:
1. Speed:         x 2.4,         to range between:  0 to  600 mm m/s
2. Direction:     x 1.5,         to range between:  0 to  360 degrees
3. Divergence:    x 0.024 - 3.0, to range between: -3 to    3 mm/hour
4. Evaporation:   x 0.003,       to range between:  0 to 0.75 mm/hour
5. Precipitation: x 0.012,       to range between:  0 to    3 mm/hour
6. Water Vapor:   x 0.3,         to range between:  0 to   75 mm
The water vapor transport direction is given in the
oceanographic convention.

The maps have:
Longitude = 0.25*xdim -  0.125 (degrees east)
Latitdue  = 0.25*ydim - 90.125
where
xdim goes from 1 to 1440 and
ydim goes from 1 to 720.
Please see the read code for full details.

Once you have further developed one of these skeleton programs
to suit your processing needs you may wish to use the verification file
to confirm that the data files are still being read correctly.  

The methodology used to produce the PMWC product is documented in:
Hilburn, K. A., (2009), The passive microwave water cycle product,
report number 072409, Remote Sensing Systems, 30 pp.

If you have any questions regarding these programs
or the RSS binary data files, please contact our support desk
at support@remss.com