2. Which one of the following is not a hyperbolic radio system? Explanation: Loran-C, Omega, Decca, and Chayka are the hyperbolic navigational systems whereas the VOR, DME falls under the point source navigational systems.

Classification

• Radiodetermination-satellite service (article 1.41)
• Radionavigation service (article 1.42) Radionavigation-satellite service (article 1.43) Maritime radionavigation service (article 1.44) Maritime radionavigation-satellite service (article 1.45) Aeronautical radionavigation service (article 1.46)

Hyperbolic location systems were first used during World War I in acoustic location systems for locating enemy artillery. The sound of a shell being fired was received by several microphones, and the time of reception sent to a computing center to plot the location. These systems were used into World War II.

The principal difference between eLoran and traditional Loran-C is the addition of a data channel in the transmitted signal. This conveys application-specific corrections, warnings, and signal integrity information to the user’s receiver.

The absolute accuracy of LORAN-C varies from 0.10 to 0.25 nmi (185 to 463 m). Repeatable accuracy is much greater, typically from 60 to 300 ft (18 to 91 m).

Loran-C was made obsolete by GPS and discontinued by the United States and Canada in 2010, as was the trial of an enhanced Loran service (eLoran) that was accurate within 65 feet. During the following five years, nearly every other country that had operated a Loran-C system shut it down.

long range navigation

The use of integrated GPS/Loran-C improve GPS availability by only a few percent. In the mountains, the use of an integrated system increases availability to 95% as compared to 65% for GPS and 75% for multi-chain Loran-C.

LORAN-C was a medium range hyperbolic radio navigation system, operated by the US Coast Guard, which allowed a receiver to determine its position by using multilateration principles to compare the difference in reception time of low frequency radio signals transmitted by a group of fixed, land-based radio beacons.

Thus at short distances the lines cross at angles close to 90 degrees, and this angle steadily reduces with range. Because the accuracy of the fix depends on the crossing angle, all hyperbolic navigation systems grow increasingly inaccurate with increasing range.

An electronic navigation unit that is approved for use under instrument flight rules as a primary means of navigation and has at least one source of navigational input, such as an inertial navigation system, global positioning system, or LORAN C.

The Decca Navigator System was a hyperbolic radio navigation system which allowed ships and aircraft to determine their position by receiving radio signals from fixed navigational beacons. The Allied forces needed an accurate system not known to the Germans and thus free of jamming.

Each chain comprised of one Master and two or three Slave stations, usually located 80 to 110 km from the Master station. The accuracy of DNS ranged from 50 meters during daytime to 200 meters at night.

By receiving signals from three stations, an Omega receiver could locate a position to within 4 nautical miles (7.4 km) using the principle of phase comparison of signals. Omega stations used very extensive antennas to transmit at their very low frequencies (VLF).

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.

along the base line bisector In a hyperbolic navigation system accuracy is greatest: along the right bisector of the baseline.

An alternative to hyperbolic mode was Range-Range mode. This involved carrying the master transmitter actually aboard the vessel, whilst the slaves remained ashore.

Omega was a very long-range Very Low Frequency (VLF) navigation system and the first navigation system providing true global coverage. The system worked by generating hyperbolic lines of position (LOP) by means of phase difference measurements of VLF time-shared transmissions emitted by widely spaced antennae.

Desmond McEvaddy

eLORAN is a high power, low-frequency, ground wave radio broadcast system capable of providing 10- to 20-meter positioning accuracy, Stratum-1 frequency distribution, and Universal Time Coordinated (UTC) timing well within 1μs across 1,000 miles or more. ( Image: Continental Electronics)

World View of eLoran During this time, eLoran was successfully tested and demonstrated in all modes: aviation, maritime, land-mobile, location-based, and timing and frequency. Further, eLoran has been successfully in operation in the U.K. for several years.

GNSS (or Global Navigation Satellite System) is a broad term encompassing different types of satellite-based positioning, navigation and timing (PNT) systems used globally. GPS (or Global Positioning System) is one such type of Global Navigation Satellite System.

Other Global Navigation Satellite Systems (GNSS)

• BeiDou / BDS (China)
• Galileo (Europe)
• GLONASS (Russia)
• IRNSS / NavIC (India)
• QZSS (Japan)

TOKYO — China’s BeiDou satellite positioning system has overtaken its U.S. rival in size, a shift with potentially huge implications for both high-tech industry and national security. The U.S. has long been the world leader in satellite-based positioning with its Global Positioning System.

As of September 2020, the United States’ Global Positioning System (GPS), Russia’s Global Navigation Satellite System (GLONASS), China’s BeiDou Navigation Satellite System (BDS) and the European Union’s Galileo are fully operational GNSSs.

Researchers from the National Space Science Centre in Beijing found that a spacecraft travelling at or below an altitude of 2,000km (1,200 miles) would be able to see 50 per cent more BeiDou satellites than those from the Global Positioning System at any given time.

The American taxpayer pays for the GPS service enjoyed throughout the world. All GPS program funding comes from general U.S. tax revenues. The bulk of the program is budgeted through the Department of Defense, which has primary responsibility for developing, acquiring, operating, sustaining, and modernizing GPS.