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Radar mile or radar nautical mile is an auxiliary constant for converting a (delay) time to the corresponding scale distance on the radar display. [1] Radar timing is usually expressed in microseconds. To relate radar timing to distances traveled by radar energy, the speed is used to calculate it.
The radar chart is a chart and/or plot that consists of a sequence of equi-angular spokes, called radii, with each spoke representing one of the variables. The data length of a spoke is proportional to the magnitude of the variable for the data point relative to the maximum magnitude of the variable across all data points.
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.
A simple calculation reveals that a radar echo will take approximately 10.8 μs to return from a target 1 statute mile away (counting from the leading edge of the transmitter pulse (T 0), (sometimes known as transmitter main bang)). For convenience, these figures may also be expressed as 1 nautical mile in 12.4 μs or 1 kilometre in 6.7 μs.
In radar-related subjects and in JTIDS, a data mile is a unit of distance equal to 6,000 feet (1,829 metres; 0.9875 nautical miles; 1.136 miles). An international mile is 0.88 data mile. The speed of light is 299,792,458 metres per second (983,571,056 ft/s), or about one foot per nanosecond .
With this calculation, the horizon for a radar at a 1-mile (1.6 km) altitude is 89-mile (143 km). 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 ...
D-VOR/DME ground station DME antenna beside the DME transponder shelter. In aviation, distance measuring equipment (DME) is a radio navigation technology that measures the slant range (distance) between an aircraft and a ground station by timing the propagation delay of radio signals in the frequency band between 960 and 1215 megahertz (MHz).
MADRE over-the-horizon radar at the NRL's Chesapeake Bay Detachment U.S. Navy Relocatable Over-the-Horizon Radar station. The most common type of OTH radar, OTH-B (backscatter), [3] uses skywave or "skip" propagation, in which shortwave radio waves are refracted off an ionized layer in the atmosphere, the ionosphere, and return to Earth some distance away.