Local WSR-88D Radars to Receive Dual Polarization Upgrade
Each of the Doppler radars in our area will be upgraded, which will take up to a two-week period.
- Paducah WSR-88D - Complete
- Fort Campbell WSR-88D - On-going
- Owensville (Evansville) WSR-88D - Beginning on or around February 4, 2013
For up to 2 weeks, each radar will be unavailalble starting at the
dates listed above to undergo an upgrade to incorporate new technology.
This much anticipated upgrade is part the NWS vision to build a
exciting upgrade will incorporate a new technology called dual-
polarization, or dual-pol. This new technology will result in 14 new
radar products that will enable us to continue improving our suite
of high quality products and services to the public. This new
technology and data will primarily help forecasters identify the type
of precipitation that is falling, as well as improve rainfall estimates.
Current NWS Doppler radars transmit and receive pulses of radio waves
in a horizontal orientation. As a result, the radar only measures the
horizontal dimensions of targets (e.g., cloud and precipitation droplets).
Dual-polarimetric radar transmits and receives pulses in both a
horizontal and vertical orientation. Therefore, the radar measures
both the horizontal and vertical dimensions of targets. Since the radar
receives energy from horizontal and vertical pulses, we can obtain
better estimates of the size, shape, and variety of targets. It is
expected that this will result in significant improvements in the
estimation of precipitation rates, the ability to discriminate between
precipitation types (e.g., hail vs. rain), and the identification of
non-meteorological returns, such as chaff, ground clutter, and smoke
plumes from wildfires that are not uncommonly detected by weather radar
systems such as WSR-88D.
Current NWS Doppler Radar Dual-Pol Radar
- Better estimation of total precipitation amounts
- Better estimation of size distribution of hydrometeors
- Much improved ability to identify areas of heavy
rainfall that are closely linked to flash floods
- Improved detection and mitigation of non-weather
related radar echoes (chaff, smoke plumes, ground clutter)
- Easier identification of the melting layer
(helpful for identifying snow levels in higher terrain)
- Improved ability to classify precipitation type
The full benefit of dual-pol radar, however, will not be fully realized until
NWS forecasters and research meteorologists develop real-time
A radio wave is a set of oscillating electric and magnetic fields, oriented 90
degrees to each other. Polarization of the wave is the direction, or orientation, of
the electric field.
The electric field is oriented horizontally, along the x-axis (blue).
The magnetic field is oriented vertically, along the y-axis (white).
The electric field is oriented veritically, along the y-axis (orange).
The magnetic field is oriented horizontally, along the x-axis (white).