WRAL WeatherCenter Blog

Can you explain the difference between the VIPER radar and the DOPPLER radar?

Posted January 24, 2007

MIKE MOSS SAYS:      Jana,      The Doppler 5000 is a radar that WRAL purchased in the late 1990s and installed just off U.S. Highway 70 near the Wake/Johnston County line. We own that radar, maintain it, and have a software package called FASTRAC for displaying it on TV and a method for transferring imagery from the system into frequently updated web graphics. On the air, we just refer to the entire radar and display software system as Doppler 5000.

VIPIR, which stands for Volumetric Imaging and Processing of Integrated Radars, is a separate software package designed to display radar imagery from multiple radar sites, and includes some capabilities that are not a part of the FASTRAC software that we've traditionally paired up with Doppler 5000. VIPIR, for example, can display near-realtime sweeps from as many as seven doppler radar sites all at the same time (we usually show our own Doppler 5000 sweep together with those from the Raleigh, Morehead City, Wilmington, Greenville-Spartanburg SC, Wakefield VA, and Blacksburg VA National Weather Service doppler radars), is able to display computer model output and satellite imagery, is able to convert the imagery from any radar or satellite source into a pseudo-3D view (helpful in highlighting the location of lightning strikes for example, or of indicating the relative heights of showers and thunderstorms, and in some cases just adding a bit to the visual appeal and variety of displays available), and can display hurricane path forecasts along with reconnaissance tracks and observations taken by hunter aircraft.

There are several areas in which VIPIR and Doppler 5000 overlap, and we make choices based on the situation, plus having both gives us a backup in case something goes wrong with one system or the other. In each case, we are able to plot storm tracks that estimate the time of arrival of a storm at communities in its path, we can show radar estimated precipitation rates or amounts and wind speeds, national radar composites based on all the NWS radars across the United States, color coded watch and warning areas, and can display some additional information like surface temperatures, ocean buoy reports, and so on. In turn, some of these capabilities are not used all that frequently, because we can show most of that information using our basic weather graphics system - again, it's nice to have a backup in that if our main graphics system were to suffer a sudden failure, we could manage at least a modest weathercast using only the capabilities of VIPIR and/or Doppler 5000.

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