7. Radio Navigation Equipment Flashcards
VOR charecteristics
VOR operates on VHF. The accuracy of the bearing is excellent, but the coverage is limited to line of sight.
DME is commonly collocated at VOR stations to provide aircraft with bearing and distance information.
RNAV routes are established along waypoints based in the bearing and distance information from VOR/ DME.
ILS components
Basic ILS components are
a localiser for lateral guidance,
a glide slope for vertical guidance and
marker beacons for position information.
NDB characteristics
NDB stations
operate on LF to MF frequencies.
ADF receivers show relative bearing to NDB station over relatively long distance.
NDB limitations
There are factors that cause deterioration in the accuracy of NDB radio signals. They are mainly
night effect,
Electrical discharge from TS
interference from adjacent frequencies and
errors caused by reflection by solid objects.
Night Effect
Night effect shortens reliable coverage of NDB.
E layer reflects LF/MF at night. The reflected LF/MF signals cause errors in directional data.
The Errors becomes greater as the distance increases.
NDB
NDB stations operate on LF to MF frequencies. ADF receivers show relative bearings to NDB stations over relatively long distances
Factors that cause deterioration of NDB signals
- night effect
- interference from adjacent frequencies
- errors caused by reflection by solid objects
- electrical discharge from TS
Night Effect
Night effect shortens reliable coverage of NDB. E layer reflects LF/MF at night. The reflected LF/MF signals cause errors in directional data. The error becomes greater as the distance increases.