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Continuous-wave radar (CW radar) is a type of radar system where a known stable frequency continuous wave radio energy is transmitted and then received from any reflecting objects. [1] Individual objects can be detected using the Doppler effect , which causes the received signal to have a different frequency from the transmitted signal ...
Synthetic-aperture radar ( SAR) is a form of radar that is used to create two-dimensional images or three-dimensional reconstructions of objects, such as landscapes. [ 1] SAR uses the motion of the radar antenna over a target region to provide finer spatial resolution than conventional stationary beam-scanning radars.
Ground-penetrating radar ( GPR) is a geophysical method that uses radar pulses to image the subsurface. It is a non-intrusive method of surveying the sub-surface to investigate underground utilities such as concrete, asphalt, metals, pipes, cables or masonry. [ 1] This nondestructive method uses electromagnetic radiation in the microwave band ...
Pulse-repetition frequency (PRF) is the number of times a pulsed activity occurs every second. This is similar to cycle per second used to describe other types of waveforms. PRF is inversely proportional to time period which is the property of a pulsed wave. PRF is usually associated with pulse spacing, which is the distance that the pulse ...
Radar loop of Hurricane Katrina making landfall in Louisiana On August 28, Alabama Governor Bob Riley declared a state of emergency for the approaching Hurricane Katrina. On the same day, he requested President Bush to declare "expedited major disaster declaration" for six counties of South Alabama, which was quickly approved.
Exercise. Staying physically active is important to maintain fluid balance in the body and prevent water retention, the experts note. Exercise can also promote fluid loss through sweating ...
Radar astronomy. Radar astronomy is a technique of observing nearby astronomical objects by reflecting radio waves or microwaves off target objects and analyzing their reflections. Radar astronomy differs from radio astronomy in that the latter is a passive observation (i.e., receiving only) and the former an active one (transmitting and ...
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