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Active sonar is similar to radar in that, while it allows detection of targets at a certain range, it also enables the emitter to be detected at a far greater range, which is undesirable. Since active sonar reveals the presence and position of the operator, and does not allow exact classification of targets, it is used by fast (planes ...
These generally use navigational radar frequencies, but modulate the pulse so the receiver can determine the type of surface of the reflector. The best general-purpose radars distinguish the rain of heavy storms, as well as land and vehicles. Some can superimpose sonar and map data from GPS position.
Light detection and ranging (LIDAR) is used for weapon ranging, laser illuminated homing of projectiles, and to detect and measure the concentration of various chemicals in the atmosphere while airborne LIDAR can be used to measure the heights of objects and features on the ground more accurately than radar technology. LIDAR can be used to ...
Lidar is a sort-of acronym that may or may not be capitalized when you see it, and it usually stands for "light detection and ranging," though sometimes people like to fit "imaging" between the ...
Sodar systems are in fact nothing more than sonar systems used in the air rather than in water. More specifically, since they operate using the Doppler effect with a multi-beam configuration to determine wind speed, they are the exact in-air equivalent to a subclass of sonar systems known as acoustic Doppler current profilers (ADCP). Other ...
Modern radar systems are generally able to smoothly change their PRF, pulse width and carrier frequency, making identification much more difficult. Sonar and lidar systems also have PRFs, as does any pulsed system. In the case of sonar, the term pulse-repetition rate (PRR) is more common, although it refers to the same concept.
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 ]
The radar mile is the time it takes for a radar pulse to travel one nautical mile, reflect off a target, and return to the radar antenna. Since a nautical mile is defined as 1,852 m, then dividing this distance by the speed of light (299,792,458 m/s), and then multiplying the result by 2 yields a result of 12.36 μs in duration.