Radio Theory Flashcards
In what Frequencies do VOR operate?
108.1 - 117.95 MHz
On what frequency does DME operate?
UHF - Ultra High Frequency
DME are often located with_____
VOR stations
What does DME do?
It measures distance in nm from the transmitter.
It can usually also calculate ground speed and ETE
What does ADF stand for?
Automatic Direction Finder
On what frequency does ADF operate?
Low frequency/medium frequency band
What is an ADF ground station know as?
NDB - non-directional beacon
What does RADAR stand for?
Radio Detection and Range
Types of Radar
Primary RADAR - radio waves reflect off the aircraft
Secondary Surveillance RADAR - requires aircraft with transponder
How many transponder codes are there?
4096
Types of Transponders
Mode C - older
Mode S - has data incorporated like aircraft ID permanently
Low and Medium Frequency band
Long range transmission is possible
Range is dependant on power output of beacon
Signal tends to follow curvature of earth
Subject to interference like Thunderstoms
High Frequency characteristics
Well suited to long range communication
Signal quality can be poor
Subject to various forms of interference
Very High Frequency characteristics
Range is subject to line of sight
Range = 1.23 x sq rt of the height.
1500’ AGL is close to 50nm
Signal quality is good (that’s why we use it for voice).
Signal travels in a straight line - useful to determine direction
UHF Characteristics
Similar in all aspects to VHF
Used for DME and TACAN
Full skilled reflection of the CDI on a GPS receiver indicates ____ of track error with each dot on the indicator equal to ___ while in en route mode.
5nm, 1nm
GPS is accurate to within___ Horizontally 95% of the time
6 metres
What is the frequency band used for VHF navigation?
108.1 to 117.95 MHz
Full skilled deflection of the CDI on a VOR receiver indicates ___ of track error with each dot on the indicator equal to ___
10°, 2°
What is the formula for the expected range of a VOR?
VHF Range = 1.23 x (sq rt of aircraft height + sq rt antenna height)
one decimal 33 times (the square root of the height of the aircraft plus the square root of the height of the ground station antenna in feet MSL)
What is the frequency band used for aeronautical communication?
118.0–136.0 MHz
Each GPS satellite has four atomic clocks accurate to within:
1, billionth of a second
What are the practical applications of low frequency waves?
NDB - but I don’t know why.
