The NEXRAD or commonly referred Next Generation Radar consists of a complex network with over 160 high resolution Doppler Weather Radars specifically using what is known as the S-band. These Doppler Radars are operated within United States of America by the National Weather Service which is an existing branch of the National Oceanic and Atmospheric Administration.
The technical name by which the NEXRAD radar is more commonly associated with is the WSR-88D radar or Weather Surveillance Radar, 1988 Doppler.
The NEXRAD radar achieves its weather readings by specifically detecting wind speeds related to movements within the atmosphere and precipitation levels over monitored areas.
These reading when obtained are decoded and displayed in what is categorically known as a mosaic map highlighting patterns of weather movement and humidity. The system used by the NERXAD radar places a particular emphasis on full automation using commands rooted in a series of algorithms to automatically scan specific areas.
NEXRAD radars can be seen to operate in two very basic modes which can be selected by the weather forecasting operator. They are, the clean air mode which is a slow and detailed scan of current wind speeds and air movements typically whenever the activity is at a low or non-existent level, and a precipitation mode which allows the radar to operate at a faster scan pace typically used when tracking and analyzing high incident or active weather.
The United States Department of Commerce, Department of Defense in collaboration with the Transport Department in the 1970’s realized the necessity to replace the existing radar network consisting of the WSR-74 and the WSR-57 radars of which neither were Doppler radars in order to improve their operational effectiveness.
In 1976 the Joint Doppler Operational Project was developed with the aim to successfully identify and improve warning times for tornado based thunderstorms. The National Weather Service over the following three years after a series of tests realized that the Doppler radar was a much improved and well needed system in providing early warnings of possible thunderstorms.
The decision to develop and deploy a system of much needed Doppler radars was taken in 1979 as the contract was commissioned to the companies Raytheon and Unisys to develop the Doppler radars. By the 1980’s the Doppler radar systems developed by both companies were already being tested which resulted in the company Unisys in January of 1990 awarded the full contract to manufacture on a full scale production.
Fall of 1990 saw the first implementation of the prototype radar in the town of Norman in the state of Oklahoma. On June 12th 1992 the first fully operational WSR-88D radar used in everyday forecast was placed in Sterling, Virginia with the final installation done on Indiana, North Webster on August 30th 1997. Since then new radar was placed in WA, Langley Hill to allow better coverage of the Pacific costal area within that region.