WSR-57

WSR-57 radars were the USA's main weather surveillance radar for over 35 years.citeweb|title=Weather service retires last of old radars|url=http://www.usatoday.com/weather/wsr57.htm|publisher=USAToday|accessdate=2008-03-27] The National Weather Service operated a network of this model radar across the country, watching for severe weather.

History

The WSR-57 (Weather Surveillance Radar - 1957) was the first 'modern' weather radar. Initially commissioned at the Miami Hurricane Forecast Center, the WSR-57 was installed in other parts of the CONUS (continental United States).citeweb|title=History of Operational Use of Weather Radar by U.S. Weather Services|url=http://ams.allenpress.com/perlserv/?request=get-document&doi=10.1175%2F1520-0434(1998)013%3C0219%3AHOOUOW%3E2.0.CO%3B2&ct=1|publisher=AMS|accessdate=2008-03-27] The WSR-57 was the first generation of radars designed expressly for a national warning network. [citeweb|title=Historic Tornado Warning Conference Launched Nation's First Weather Radar Network|url=http://www.noaanews.noaa.gov/stories/s1163.htm|publisher=NOAA|accessdate=2008-03-27]

The WSR-57 was designed in 1957 using World War II technology. It gave only coarse reflectivity data and no velocity data, which made it extremely difficult to predict tornadoes. Weather systems were traced across the radar screen using grease pencils. Forecasters had to manually turn a crank to adjust the radar's scan elevation, and needed considerable skill to judge the intensity of storms based on green blotches on the radar scope.

The military designation for the WSR-57 is AN/FPS-41.

NOAA has interesting pictures of the Charleston, SC [http://www.photolib.noaa.gov/htmls/wea00455.htm WSR-57 radar image] of Hurricane Hugo in 1989. At the National Hurricane Center (NHC), Hurricane Andrew in 1992 blew the WSR-57 dish off their roof. [citeweb|title=Case Study: Hurricane Andrew|url=http://ivis.eps.pitt.edu/courses/hazards/lectures/21.pdf|publisher=pitt.edu|accessdate=2008-03-27] The NHC report on Hurricane Andrew shows its last radar image, as well as images from nearby WSR-88D radars. [citeweb|title=Preliminary Report Hurricane Andrew 16 - 28 August, 1992|url=http://www.nhc.noaa.gov/1992andrew.html|publisher=NOAA|accessdate=2008-03-27]

As the network of WSR-57 radars aged, some were replaced with WSR-74S models of simiar performance but with better reliability. WSR-57 operators sometimes had to scramble for spare parts no longer manufactured in this country. One Hundred and twenty eight (128) of the WSR-57 and WSR-74 model radars were spread across the country as the National Weather Service's radar network until the 1990's. [citeweb|title=An Overview of NEXRAD Products Available via UCAR's Unidata Program|url=http://sysu1.wsicorp.com/unidata/intro.html|publisher=wsicorp.com|accessdate=2008-03-27] They were gradually replaced by the WSR-88D model (Weather Surveillance Radar - 1988, Doppler), constituting the NEXRAD network.

The last WSR-57 radar in the United States was decommissioned on December 2, 1996.

Radar sites

The 66 former sites of the WSR-57 include [citeweb|title=Assessment of Nexrad Coverage and Associated Weather Services (1995)|url=http://books.nap.edu/books/NI000004/html/9.html|publisher=books.nap.edu|accessdate=2008-03-27] [citeweb|title=Report of US Weather Bureau Studies in Radar Hydrology|url=http://www.cig.ensmp.fr/~iahs/redbooks/a065/065028.pdf|publisher=cig.ensmp.fr|accessdate=2008-03-27] [citeweb|title=NWS Offices Past and Present|url=http://www.dm.net/~chris-g/nwshist.html|publisher=dm.net|accessdate=2008-03-27] the following:

Radar properties

• The radar uses a wavelength of 10.3 cm.citeweb|title=WSR - Weather Surveillance Radar|url=http://weather.cod.edu/sirvatka/radar.html|publisher=weather.cod.edu|accessdate=2008-03-27] This corresponds to an operating frequency of 2890 MHz. This frequency is in the S band, which is also used by today's weather radar network.

• WSR-57 radars had the following interesting statistics:
  • Dish diameter: 12 feet
  • Power output: 410,000 watts
  • Maximum range: 915 km (494 nm)

References