NWS IND Stakeholder's Blog

Indianapolis Doppler Radar to Be Upgrade to Dual Polarization

On the morning of August 28, 2012, the National Weather Service in Indianapolis issued the following statement:

...INDIANAPOLIS DOPPLER RADAR UPGRADE SCHEDULED FOR OCTOBER...

THE INDIANAPOLIS WSR-88D DOPPLER RADAR /KIND/ IS SCHEDULED FOR A
MAJOR UPGRADE TO DUAL POLARIZATION IN OCTOBER. CURRENTLY...THE
RADAR IS SCHEDULED TO BE TAKEN OUT OF SERVICE ON MONDAY OCTOBER
15TH...AND REMAIN OUT OF SERVICE FOR UP TO TEN DAYS. DURING THIS
PERIOD...A NATIONAL INSTALLATION TEAM WILL PERFORM SIGNIFICANT
HARDWARE AND SOFTWARE MODIFICATIONS ON THE RADAR...AS WELL AS
MONITORING AND CALIBRATION NEAR THE END OF THIS PERIOD.

DURING THE TIME KIND IS OUT OF SERVICE...DATA FROM KIND WILL BE
UNAVAILABLE...AND SURROUNDING RADARS AS WELL AS THE INDIANAPOLIS
TERMINAL DOPPLER WEATHER RADAR WILL PROVIDE RADAR COVERAGE FOR
CENTRAL INDIANA. BACKUP RADARS FOR INDIANAPOLIS INCLUDE CHICAGO
/KLOT/...NORTHERN INDIANA /KIWX/...WILMINGTON OHIO
/KILN/...LOUISVILLE KENTUCKY /KLVX/...PADUCAH KENTUCKY
/KPAH/...EVANSVILLE INDIANA /KVWX/...AND CENTRAL ILLINOIS /KILX/.

THIS UPGRADE IS PART OF A LARGER SCALE UPGRADE TO THE NATIONAL 
NETWORK OF DOPPLER RADARS. THE UPGRADE WILL ALLOW THE RADAR TO SEND 
BOTH HORIZONTALLY AND VERTICALLY ORIENTED PULSES OF ENERGY...WHICH 
WILL PROVIDE NEW INFORMATION ON THE THREE DIMENSIONAL 
CHARACTERISTICS OF SCATTERERS IN THE ATMOSPHERE...SUCH AS 
RAINDROPS...HAILSTONES...SNOWFLAKES...OR EVEN DUST...BUGS...AND 
OTHER BIOLOGICAL TARGETS. THIS INFORMATION WILL HELP TO IMPROVE 
FORECASTERS DIAGNOSIS AND TRACKING OF HAIL WITHIN 
THUNDERSTORMS...HEAVY RAINFALL DURING POTENTIAL FLOOD EVENTS...AND 
PRECIPITATION TYPE AND TRANSITIONS DURING WINTER STORMS...AS WELL AS 
PROVIDING IMPROVED RADAR ESTIMATES OF PRECIPITATION ACCUMULATION.

INFORMATION AND TRAINING FOR NWS PARTNERS ON DUAL POLARIZATION 
TECHNOLOGY IS AVAILABLE VIA THE NWS WARNING DECISION TRAINING BRANCH 
AT THE FOLLOWING URL.

HTTP://WWW.WDTB.NOAA.GOV/COURSES/DUALPOL/OUTREACH/INDEX.HTML

FOR MORE INFORMATION ABOUT THE DUAL POLARIZATION UPGRADE AT
INDIANAPOLIS...PLEASE CONTACT:DANIEL MCCARTHY - METEOROLOGIST IN CHARGE
EMAIL - DANIEL.MCCARTHY@NOAA.GOV
PHONE - 317-856-0360

This is an exciting time for central Indiana as this upgrade is the most significant enhancement to the nation’s Doppler radar in more than 20 years.  This upgrade will allow forecasters to improve weather forecasts and convey impacts due to rain, winter weather, flooding and tornadoes.  This upgrade is one of the early steps to build a Weather Ready Nation enhancing confidence in order for partners, stakeholders, emergency management, first responders and media to work together for governments, private industry and the general pubic to make quick decisions in protecting lives and livelihoods.

Dual Polarization Radar Concept

The National Weather Service Doppler radars (WSR-88D) are in the process of being upgraded to polarmetric, more commonly known as “dual-pol” this year. In fact, the National Weather Service Forecast Office at Indianapolis is scheduled to be upgraded to dual-polar in late October 2012. The added dual polarization will provide vertical as well as horizontal pulses that are currently transmitted by and reflected back to the radar.

Fig. 1: Conceptualization of Conventional Radar versus Dual Polarization Radar

Benefits of Dual polarization

The result will allow forecasters to much better detect precipitation intensity…large hail and cold season precipitation. It will also give forecasters confirmation on tornado destruction as it can detect tornado debris lifted aloft. The result is expected to be big improvements in flash flood warnings…severe thunderstorm warnings and winter forecasting type identification as well as tornado confirmation and tracking. Besides the public benefits, dual polarization will also aid in aviation forecasting as it can better detect birds and icing, two deterrents to flying.

Fig. 2: 4-panel display of a tornadic storm from the Dual-Pol Radar in Huntsville, AL. The panel in the lower left shows a display of Correlation Coefficient displaying brightly tornado debris.

For more information on Dual-Polarization radar see the following link Questions and Answers.
Michael Koch and Dan McCarthy