Search results
Results From The WOW.Com Content Network
The frequency of radio waves used by most radars, in the form of microwaves, travel in straight lines.This generally limits the detection range of radar systems to objects on their horizon (generally referred to as "line of sight" since the aircraft must be at least theoretically visible to a person at the location and elevation of the radar transmitter) due to the curvature of the Earth.
An over-the-horizon radar sited in the USSR would help solve this problem, and work on such a system for this associated role started in the late 1960s. The first experimental system, Duga, was built outside Mykolaiv in Ukraine , successfully detecting rocket launches from Baikonur Cosmodrome at 2,500 kilometres (1,600 mi).
AN/APS-21 search radar by Westinghouse Electric (1886) for part of AN/APQ-35 for Douglas F3D Skynight and Gloster Meteor NF; AN/APS-23 search radar by Western Electric for Convair B-36 North American B-45C Tornado Boeing B-47E Stratojet B-50 Superfortress B-52 Stratofortress Lockheed C-130 Hercules and Boeing C-135 Stratolifter part of AN/ASB-3
A radar with a 1° horizontal beamwidth that sweeps the entire 360° horizon every 2 seconds with a PRF of 1080 Hz will radiate 6 pulses over each 1-degree arc. If the receiver needs at least 12 reflected pulses of similar amplitudes to achieve an acceptable probability of detection, then there are three choices for the designer: double the PRF ...
The frequency selection of weather radar is a performance compromise between precipitation reflectivity and attenuation due to atmospheric water vapor. Some weather radars uses doppler shift to measure wind speeds and dual-polarization for identification of types of precipitations.
Container (29B6) radar (Russian: 29Б6 «Контейнер») is the new generation of Russian over-the-horizon radar, providing long distance airspace monitoring and ballistic missile detection. The first radar, near Kovylkino , Mordovia , Russia , became operational in December 2013 [ 1 ] [ 3 ] [ 4 ] and entered combat duty on 1 December ...
The United States military unleashed a wave of attacks targeting radar sites operated by Yemen's Houthi rebels over their assaults on shipping in the crucial Red Sea corridor, authorities said ...
The radar horizon with an antenna height of 75 feet (23 m) over the ocean is 10-mile (16 km). However, since the pressure and water vapor content of the atmosphere varies with height, the path used by the radar beam is refracted by the change in density. With a standard atmosphere, electromagnetic waves are generally bent or refracted downward.