CFII oral exam guide questions?
"Jose" wrote in message . com...
Well, Jim, it almost COULD work that way, but it doesn't. :-[
VOR azimuth angle is measured by a phase comparison
between two sinusoidal signals, not a time-delay measurement.
The VOR reference signal is frequency modulated on a subcarrier,
while the azimuth signal is from amplitude modulation on the
radio-frequency carrier, caused by the VOR's rotating cardioid beam.
It's indirect, but isn't a measurement of phase difference of two
different waves the same as the measurement of the time difference
between crests (once you take into account the frequency and the speed
of light)? It's like saying the alimiter measures altitude. It's not
technically correct (and yes, the difference is meaningful under some
circumstances) but gets the job done.
Jose
--
The time domain and the frequency domain are related conventionally
through a mathematical manipulation called the Fourier Transform.
However, the measurement methods used in the two domains
are considerably different.
The VOR system was designed for measurements in phase space.
DME, of course, was designed for the time domain.
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