308
15 Goniometric Radio Navigation Systems
Fig. 15.28 Waveform diagrams in ARC comparison circuit with inner phase modulation
Hence, information on direction of radio waves arrival, concluding in amplitude
and initial phase of a signal of frame antenna, converted, correspondingly, into index
and sign of phase modulation of combined signal. At frame turn by zero reception into
direction to LB, we obtain a minimum of phase modulation depth. At summation of
oscillations, the resulting signal amplitude is also changed, i.e., there is also amplitude
modulation with 2F frequency. This amplitude modulation is considered as parasitic,
i.e., interfering, and therefore, in the further ARC cascades should be eliminated.
Elimination is conducted using an amplitude limiter. In this case, we get an extra
bonus, since at amplitude limiting the influence of LB call signals on operation of
ARC compass part is eliminated. Using the following ARC circuits, we can extract
a voltage, an amplitude and phase of which corresponds to phase change law of
phase-modulated oscillation, and use it as a signal, feeding the control winding of
motor.
Let’s examine some facts and phenomena effecting on HA calculation error.
“Coastal effect” is exerted at flights near sea shore. Radio waves, radiated by
locator beacons, located on surface, at intersection of two mediums borders with
different electrical properties, change a propagation direction (kind of deflected).
15 Goniometric Radio Navigation Systems
Fig. 15.28 Waveform diagrams in ARC comparison circuit with inner phase modulation
Hence, information on direction of radio waves arrival, concluding in amplitude
and initial phase of a signal of frame antenna, converted, correspondingly, into index
and sign of phase modulation of combined signal. At frame turn by zero reception into
direction to LB, we obtain a minimum of phase modulation depth. At summation of
oscillations, the resulting signal amplitude is also changed, i.e., there is also amplitude
modulation with 2F frequency. This amplitude modulation is considered as parasitic,
i.e., interfering, and therefore, in the further ARC cascades should be eliminated.
Elimination is conducted using an amplitude limiter. In this case, we get an extra
bonus, since at amplitude limiting the influence of LB call signals on operation of
ARC compass part is eliminated. Using the following ARC circuits, we can extract
a voltage, an amplitude and phase of which corresponds to phase change law of
phase-modulated oscillation, and use it as a signal, feeding the control winding of
motor.
Let’s examine some facts and phenomena effecting on HA calculation error.
“Coastal effect” is exerted at flights near sea shore. Radio waves, radiated by
locator beacons, located on surface, at intersection of two mediums borders with
different electrical properties, change a propagation direction (kind of deflected).