Gee Navigation System

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Armeza.Landicho.Sinigayan.Zarraga


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1935 GEE was developed by Robert J. Dippy

also known as AMES Type 7000

Gee used three transmitters (one "master" and two "slaves)

The name "Gee" was actually short for "Grid".

- designed as a short-range blind landing system to improvesafety during night operations, but it developed into a long-

range general navigation system.

- the electronic grid of latitude and longitude derived from thecombination of three signals received by the aircraft.

It was the first hyperbolic navigation system to be used

operationally.


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GEE RECEIVER GEE TRANSMITTER

GEE WSC19 & WSC62 GEE TEACHING SET TYPE 30


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GEE LATTICE


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- calculate the time difference between two radio pulses, andthose that compare the phase difference between twocontinuous signals.

- is a class of radio navigation systems based which determinesposition based on the microsecond difference in timing between

the reception of two signals.

- requires the plotting all of the potential locations of the receiverfor the measured delay. This produces a series of hyperbolic lines(a parabola) on a chart.


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-used an arrangement with one master and (typically) three slaves.The signals from the master and either of the two slaves would beactive at any time, with the third station and a chain monitor stationproviding backup and signal quality measurements.

The transmitters had a power output of about 300 kW and operatedin four frequency bands between 20 and 85 MHz.

A collection of such stations was known as a "chain"


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Used of the H-principle or Twin-range principle

Also known as Ames 100


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Gee worked on the principle of measuring the difference inarrival time of pulses from two transmitters located in the U.K.

By measuring this time difference and relating it to similarlymarked lines on a map you could identify which line you wereon.

Repeating this a second time using another pair of pulses and asecond set of lines on the map, your position could bedetermined. One master station, the 'A' station, was commonto both sets of pulses such that three transmitters were onlyrequired rather than four.

The indicator unit had an extremely accurate time measuringsystem that could result in distance measuring resolutions ofbetter than 1 mile.


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To measure the exact time it took for a signals to reach thereceiver, the receiver must know the exact time the signal wastransmitted.

The most common clock to use with GEE was a crystaloscillator.


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Accurate navigation by day and night

The use of GEE enabled the navigator to calculateeasily the wind direction and speed, en route and overthe target

Gee offered enough accuracy to be used as an aiming

reference without the need to use a bombsight or otherexternal reference.

Highly susceptible to jamming


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World War II

Royal Navy

RAF Bomber Command

Photo Reconnaissance Mosquitoes

USAAF 8th, 9th, 12thand 13th Air Forces

Gee Navigation System

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