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At any range, with similar azimuth and elevation angles and as viewed by a radar with an unmodulated pulse, the range resolution is approximately equal in distance to half of the pulse duration times the speed of light (approximately 300 meters per microsecond). Radar echoes, showing a representation of the carrier
Radar is a system that uses radio waves to determine the distance (), direction (azimuth and elevation angles), and radial velocity of objects relative to the site. It is a radiodetermination method [1] used to detect and track aircraft, ships, spacecraft, guided missiles, motor vehicles, map weather formations, and terrain.
This determines the minimum range of the system. Longer pulses mean that more energy has the potential to be reflected by the object. However, the radar system cannot detect reflections while it is sending a pulse. To have a 30 km minimum range, for instance, a radar can have pulses no longer than 0.1 ms in duration.
Range and velocity can both be identified using medium PRF, but neither one can be identified directly. Medium PRF is from 3 kHz to 30 kHz, which corresponds with radar range from 5 km to 50 km. This is the ambiguous range, which is much smaller than the maximum range. Range ambiguity resolution is used to determine true range in medium PRF radar.
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.
The range resolution is the minimal range separation between two objects traveling at the same speed before the radar can detect two discrete reflections: = (). In addition to this sampling limit, the duration of the transmitted pulse could mean that returns from two targets will be received simultaneously from different parts of the pulse.
And for the same examples : the radar horizon for the radar at a 1-mile (1.6 km) altitude will be 102-mile (164 km) and the one at 75 feet (23 m) will be 12-mile (19 km). Furthermore, layers with an inverse trend of temperature or humidity cause atmospheric ducting , which bends the beam downward or even traps radio waves so that they do not ...
Radar cross-section (RCS), denoted σ, also called radar signature, is a measure of how detectable an object is by radar. A larger RCS indicates that an object is more easily detected. [1] An object reflects a limited amount of radar energy back to the source. The factors that influence this include: [1] the material with which the target is made;