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Description of the radar set, tactical-technical characteristics

Figure 1: WSR-74S

Figure 1: WSR-74S

frequency: 2 890 MHz
(S band)
5 625 MHz
pulse repetition time (PRT):
pulse repetition frequency (PRF): 160 or 640 Hz250 … 1500 Hz
pulsewidth (τ): 4 or 1 µs3 µs
receiving time:
dead time:
peak power: 500 kW240 kW
average power:
instrumented range: 460 km
range resolution:
beamwidth: 1.6°
hits per scan:
antenna rotation: 6 rpm12.5 rpm


The WSR-74 (abbreviation of Weather Surveillance Radar, Model 74) was developed in 1974 to replace and supplement the U.S. National Weather Service weather radar network operating on WSR-57. There were versions for two different frequency ranges. They were gradually replaced by the WSR-88D Doppler radar starting in 1988.


The WSR-74S operated in the S band with a magnetron as the transmitter. It used an 12-foot-diameter parabolic antenna fed by a horn radiator. Only 5 of these versions were produced to replace the losses of some WSR-57s in the network.


The WSR-74C operated in C-band with a klystron as the transmitter and used a 12-foot-diameter parabolic antenna. The radar was used as a local weather radar for thunderstorm warnings and replaced the obsolete AN/FPS-77.

Initially, a complete volume scan took about 5 minutes. From April 2000, with the modernization of the program “WSR-74C/IRIS”, a new scan strategy was used with only 2.5 minutes duration and 12 different elevation angles between 0.5° and 25.9°.

68 of these types of radars were built. The last WSR-74C was decommissioned on December 31, 2012.