Transmitting techniques of Glide Slope

TRANSMITTING TECHNIQUES FOR GLIDE SLOPE

©Anil Rai (angban401@gmail.com)

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Presented by:Anil Rai (804012)BE Elx and Comm

10 August 2011

GLIDE SLOPE Glide Path is the

vertical antenna located on one side of the runway about 300 m to the end of runway.

Aids the pilot in making his/her approach at the proper elevation angle to the runway.

Consists of a group of transmitters and antennas positioned beside the runway.

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©Anil Rai (angban401@gmail.com)

GLIDE SLOPE

The antenna radiation pattern has a 1o beamwidth, and elevated about 2.5o to 2.75o in the direction of approach.

The UHF frequencies used for the glide slope are in the range 328 to 336 MHz.

The useful range of the system is about 40 km.

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©Anil Rai (angban401@gmail.com)

GLIDE SLOPE

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FREQUENCY ARRANGEMENT

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Glide slope

Localizer

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GLIDE SLOPE DDM SENSITIVITY

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90Hz

150Hz

DDM=0.175

DDM=0.175

©Anil Rai (angban401@gmail.com)

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SIGNAL FEED TO THE GLIDE SLOPE ANTENNA

1.Null reference Glide Slope: is good for flat terrain2 antennas are used:

SBO from upper antennaCSB from lower antenna

GS

runway

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CONTINUE…

2.Dual Frequency Capture Effect Glide Slope:

3 antennas are used: SBO & Course signal Upper antennaCSB and SBO Middle antennaCSB, SBO & Clearance Lower antenna

GS

runway

Hills

©Anil Rai (angban401@gmail.com)

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CONTINUE…

3. Sideband reference Glide Slope:

2 antennas are usedheight of antenna smaller

SBO Upper antennaSBO & CSB Lower antenna

terrain

GS

runway

©Anil Rai (angban401@gmail.com)

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GLIDE PATH INDICATIONS

Needle indicates above/below glide path.

Centered Needle = Correct Glide path

©Anil Rai (angban401@gmail.com)

SUMMARY

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Localizer: horizontal guidance

Glide Path: vertical guidance

Marker Beacons: the height aircraft

©Anil Rai (angban401@gmail.com)