Hyperbolic Navigation
Hyperbolic navigation
Hyperbolic navigation refers to a class of radio navigation systems based on the difference in timing between the reception of two signals, without reference to a common clock. This timing reveals the difference in distance from the receiver to the two stations. Plotting all of the potential locations of the receiver for the measured delay produces a series of hyperbolic lines on a chart. Taking two such measurements and looking for the intersections of the hyperbolic lines reveals the receiver's location to be in one of two locations. Any form of other navigation information can be used to eliminate this ambiguity and determine a fix.
The first such system to be used was the World War II-era Gee, introduced by the Royal Air Force for use by Bomber Command. This was followed by the Decca Navigator System in 1944 by the Royal Navy, along with LORAN by the US Navy for long-range navigation at sea. Post war examples including the well-known US Coast Guard LORAN-C, the international Omega system, and the Soviet Alpha and CHAYKA. All of these systems saw use until their wholesale replacement by satellite navigation systems like the Global Positioning System (GPS).
Basic concepts
Timing-based navigation
Consider two ground-based radio stations located at a set distance from each other, say 300 km so that they are exactly 1 ms apart at light speed. Both stations are equipped with identical transmitters set to broadcast a short pulse at a specific frequency. One of these stations, called the "secondary" is also equipped with a radio receiver. When this receiver hears the signal from the other station, referred to as the "master", it triggers its own broadcast. The master station can then broadcast any series of pulses, with the secondary hearing these and generating the same series after a 1 ms delay.
Consider a portable receiver located on the midpoint of the line drawn between the two stations, known as the baseline. In this case, the signals
Hyperbolic navigation refers to a class of radio navigation systems based on the difference in timing between the reception of two signals, without reference to a common clock. This timing reveals the difference in distance from the receiver to the two stations. Plotting all of the potential locations of the receiver for the measured delay produces a series of hyperbolic lines on a chart. Taking two such measurements and looking for the intersections of the hyperbolic lines reveals the receiver's location to be in one of two locations. Any form of other navigation information can be used to eliminate this ambiguity and determine a fix.
The first such system to be used was the World War II-era Gee, introduced by the Royal Air Force for use by Bomber Command. This was followed by the Decca Navigator System in 1944 by the Royal Navy, along with LORAN by the US Navy for long-range navigation at sea. Post war examples including the well-known US Coast Guard LORAN-C, the international Omega system, and the Soviet Alpha and CHAYKA. All of these systems saw use until their wholesale replacement by satellite navigation systems like the Global Positioning System (GPS).
Basic concepts
Timing-based navigation
Consider two ground-based radio stations located at a set distance from each other, say 300 km so that they are exactly 1 ms apart at light speed. Both stations are equipped with identical transmitters set to broadcast a short pulse at a specific frequency. One of these stations, called the "secondary" is also equipped with a radio receiver. When this receiver hears the signal from the other station, referred to as the "master", it triggers its own broadcast. The master station can then broadcast any series of pulses, with the secondary hearing these and generating the same series after a 1 ms delay.
Consider a portable receiver located on the midpoint of the line drawn between the two stations, known as the baseline. In this case, the signals