CASES Precip Events
Precip Measurement and CASES
The scientific justification for S-Pol participation in CASES included
the use of a research-quality polarimetric radar for the validation
and development of alogorithms for the real-time quanitative estimate
of precipitation accumulation. Comparision of polarimetric estimates
to current NEXRAD estimates may provide a justification for modifying
NEXRAD systems to systems with full polarimetric capabilities, as well
as provide guidelines for selection of appropriate algorithms.
So far during CASES, S-Pol has recorded data for six major
precipitation events that will be used for evaluation of various
dual-polarization algorithms. As a quick-look product, mpeg movies
have been made of the data for those events. Click on the 
symbol, below, to review those movies. Note that you must
have an appropriate mpeg-viewer, and that these movies are fairly
large (sizes noted in parantheses).
1 01-May 23:30 to 02-May 08:10 (4.5 Mbytes)
2 07-May 17:44 to 08-May 06:10 (6.0 Mbytes)
3 18-May 22:40 to 19-May 08:00 (4.7 Mbytes)
19-May 08:00 to 19-May 17:00 (4.1 Mbytes)
4 25-May 20:44 to 26-May 05:10 (4.4 Mbytes)
5 26-May 23:46 to 27-May 03:00 (1.9 Mbytes)
6 29-May 17:56 to 30-May 04:45 (4.3 Mbytes)
30-May 04:45 to 30-May 15:30 (5.4 Mbytes)
7 12-Jun 06:00 to 12-Jun 10:30 (1.7 Mbytes)
8 13-Jun 01:20 to 13-Jun 09:30 (3.1 Mbytes)
13-Jun 09:30 to 13-Jun 17:20 (3.4 Mbytes)
9 16-Jun 02:00 to 16-Jun 09:00 (2.7 Mbytes)
10 17-Jun 01:00 to 17-Jun 04:20 (2.3 Mbytes)
About These Movies/Images
Copies of these movie files are available for users who may not have
access to high-bandwidth internet connections. Individual gif
image frames will be made available in the near future, providing a
clarity not available in the mpeg movies.
Two parameters are shown in the movie panels: S-Pol reflectivity, and
radial velocity. Grey areas in the reflectivity panels indicate
off-scale (high) values of reflectivity (reflectivity greater than 58
dBZ); occasional artifacts in the velocity are due to a combination of
velocity folding and differential phase shift of the
horizontally/vertically polarized signal return. Range rings in the
movies are spaced at 20-km intervals.
The main area of interest for precipitation accumulation is over the
Walnut River Watershed. A gif image showing the location of the
watershed in relation to the radar is available.
Document Maintenance:
Bob Rilling, / NCAR Atmospheric Technology Division
Created: 7-Jun-1997
Last modified: Fri Jul 18 12:45:14 MDT 1997
