Navaid Principle of Operation RNAV

The principle of operation of each navaidnavaid —Navigation Aid needs to be known and understood, as many of the errors and problems their inventors had (and solutions to those errors) can be inferred if the principle is understood.

Note that attention to detail is important here: “Depth of modulation” is different from “Difference in depth of modulation”, the latter being the correct answer for the ILSILS —Instrument Landing System localiser and glideslope. Certain navaidnavaid —Navigation Aids have a similar principle of operation, so for example, all primary radars and the DMEDME —Distance Measuring Equipment have a pulse that goes to its target and back, making their principle “slant range by pulse timing.”

You will frequently find that the principles of operation of other navaidnavaid —Navigation Aids are given as wrong answers, so ensure you have read the question - it is all too easy to recognise a principle you know, only to find that the question was asking about a different navaidnavaid —Navigation Aid.