What is a Decca chain?

What is a Decca chain?

[′dek·ə ‚chān] (navigation) A system or combination of three slave radio transmitting stations disposed about a master Decca station. Also known as star chain.

How many unique locations are defined on a hyperbolic line of position?

The two curves will normally intersect at two locations, so some other navigation system or a third measurement is needed to determine the exact location. Hyperbolic location systems were first used during World War I in acoustic location systems for locating enemy artillery.

What type of transmitter is used in a Decca system?

What type of transmitter is used in a Decca system? Explanation: A typical Decca chain consists of a master station and three slave stations. A station has a 2kW crystal controlled transmitter feeding a 300ft antenna.

What is hyperbolic line of position?

Definition. A Hyperbolic Navigation System is a system that produces hyperbolic lines (or surfaces) of position by measuring the difference in times of reception or in phase difference between radio signals from two or more synchronized transmitters.

Which of the following describes the Decca Navigator System?

The Decca Navigator System was a hyperbolic radio navigation system which allowed ships and aircraft to determine their position by using radio signals from a dedicated system of static radio transmitters.

When was Decca developed?

In 1945, the Decca Navigator Co, Ltd was formed and the first commercial chain of stations established in south-east England in 1946.

What does Loran mean?

long-range navigation
loran, abbreviation of long-range navigation, land-based system of radio navigation, first developed at the Massachusetts Institute of Technology during World War II for military ships and aircraft located within 600 miles (about 970 km) of the American coast.

What is the difference between e Loran and Loran-C?

The principal difference between eLoran and traditional Loran-C is the addition of a data channel on the transmitted signal. eLoran is also capable of providing the exceedingly precise time and frequency references needed by the telecommunications systems that carry voice and internet communications.

What is the minimum number of transmitter stations required for a Loran system?

What is the minimum number of transmitter stations required for a Loran system? Explanation: Loran consists of transmitter stations in groups forming chains. At least three transmitter stations make up a chain.

What is the pulse frequency used in Loran?

Signal Transmission The Loran-C navigation signal was a carefully structured sequence of brief radio frequency pulses transmitted on a carrier wave centered at 100 kHz. All Secondary stations radiate pulses in bursts of eight, whereas the Master signal, for identification purposes, has an additional ninth pulse burst.

What does Omega and Decca have in common?

What does Omega and Decca have in common? Explanation: Omega and Decca measure the phase differences between the signals transmitted from pairs of stations while the Loran-C and Chayka measure the time difference between the signal from two or more transmitting stations. Loran-C is a line of sight navigational system.

What was the operating principle of the Decca system?

As with most such systems, for example Decca, the operating principle was that the transmitters radiated a carrier phase locked to an accurate source, and the receiver measured the difference in phase between the signals received from the three transmitters.

How many lanes are there in a Decca?

The areas between the lines of zero phase difference in a Decca pattern are known as “lanes”. The width of each lane on the base-line is approximately Red: 450 metres, Green: 590 metres and Purple: 350 metres. Lanes are grouped into Zones. Each Zone contains 24 Red lanes, 18 Green lanes, or 30 Purple lanes.

What was the phase difference of the Decca Navigator System?

The phase difference between the signals received from stations A (Master) and B (Slave) is constant along each hyperbolic curve. The foci of the hyperbola are at the transmitting stations, A and B. The Decca Navigator System consisted of a number of land-based radio beacons organised into chains.

How is the phase of a DECCA chain determined?

All stations in a Decca chain must ‘phase locked’, and this has to be done over an appreciable distance separating the stations, sometimes up to 100 nautical miles, the phase difference being determined by this distance.

https://www.youtube.com/watch?v=HlKFaIaaZWs