Weather Surveillance Radar

Weather radar, also called weather surveillance radar (WSR) and Doppler weather radar, is a type of radar used to locate precipitation, calculate its motion, and estimate its type (rain, snow, hail etc.). Modern weather radars are mostly pulse-Doppler radars, capable of detecting the motion of rain droplets in addition to the intensity of the precipitation.

Both types of data can be analyzed to determine the structure of storms and their potential to cause severe weather.

During World War II, radar operators discovered that weather was causing echoes on their screen, masking potential enemy targets. Techniques were developed to filter them.

Raw images are routinely used and specialized software can take radar data to make short term forecasts of future positions and intensities of rain, snow, hail, and other weather phenomena. Radar output is even incorporated into numerical weather prediction models to improve analyses and forecasts.


http://en.wikipedia.org/wiki/Weather_surveillance_radar


 
Benefits of the WSR-88D over the WSR-57

• Improved Sensitivity - This is basically a result of a greater amount of power transmitted and a greater ability to distinguish smaller returns. The WSR-88D's ability to detect lighter amounts of precipitation has allowed for the detection of very light precipitation and even subtle clear air boundaries.
• Improved Resolution - This is primarily a function of angular beam width. The narrower the beam, the smaller the width at a given distance. This will allow the WSR-88D to differentiate between objects, thereby increasing the resolution.
• Volume Scanning - Rather than scanning along varying azimuth angles (PPI) then stopping to scan vertically (RHI), the radar will automatically scan various elevation angels while spinning around 360° of azimuth. Computers will generate products based on this volume scan.
• Enhanced Capabilities and Algorithms - Sophisticated computer programs will assist the radar operator to detect various phenomena such as mesocyclones and tornadoes (Tornado Vortex Signature - TVS) and the like. The radar will also have a greater range of reflectivities operating in severe and non-precipitation modes.