The scanner for the one-megawatt AN / APS-20 Seasearch S-band Radio Detection and Ranging ( RADAR ), manufactured by Hazeltine Corporation / General Electric, was ventrally mounted in a bulbous housing below the redundant bomb bay, with the RADAR relay transmitter, Identification friend or foe ( IFF ), Radio Direction Finder ( RDF ), Instrument Landing System ( ILS ), and LOng RAnge Navigation ( LORAN ) also being installed during conversion.

* LOng RAnge Navigation ( LORAN ).

Most capable of these was LORAN, for " LOng-range Aid to Navigation ", originally developed for navigation over the Atlantic.

Alfred Lee Loomis ( November 4, 1887 – August 11, 1975 ) was an American attorney, investment banker, philanthropist, scientist / physicist, pioneer in military radar usages, inventor of the LORAN or Long Range Navigation System, and lifelong patron of scientific research.

Originally known as " LRN " for Loomis Radio Navigation, LORAN was invented by Loomis.

* Long-range Navigation ( LORAN ): This was the predecessor of GPS and was ( and to an extent still is ) used primarily in commercial sea transportation.

* LORAN, a terrestrial radio navigation system originally known as LRN for Loomis Radio Navigation

It was first operated by the US Coast Guard beginning in the early 1960's as a LORAN ( Long Range Aid to Navigation ) Station.

* LORAN Station-located in Norte, Santa Bárbara ; Longe-Range Navigation Station operated by NATO, deactivated and in ruins since 1980.

The design of GPS is based partly on similar ground-based radio-navigation systems, such as LORAN and the Decca Navigator developed in the early 1940s, and used during World War II.

The most recent version of LORAN in use is LORAN-C, which operates in the low frequency ( LF ) portion of the radio spectrum from 90 to 110 Kilohertz.

A crude diagram of the LORAN principle — the difference between the time of reception of synchronized signals from radio stations A and B is constant along each hyperbolic curve ; when demarcated on a map, such curves are known as " TD lines "

The navigational method provided by LORAN is based on measuring the time difference between the receipt of signals from a pair of radio transmitters.

In practice, LORAN is implemented in integrated regional arrays, or chains, consisting of one primary station and at least two ( but often more ) secondary stations, with a uniform group repetition interval ( GRI ) defined in microseconds.

The nature of the received signal is not important, although widely available timing and navigation systems such as GPS or LORAN are convenient.

In the western hemisphere, its main use is for aircraft beacon, navigation ( LORAN ), information, and weather systems.

It was the most widely used long-range navigation system until the advent of GPS ( which was developed from it and only became available to the public in 2000 ) and LORAN is being enhanced and retained as a land-based alternative to the satellite-based system.

The indicator is also used to reject messages concerning certain optional subjects which are not required by the ship ( e. g. LORAN C messages might be rejected in a ship which is not fitted with a LORAN C receiver ).

* LORAN, a terrestrial radio-based navigation system

* LORAN, low frequency terrestrial radio navigation system, still in use ( US and Canadian operations terminated 2010 ).

Early predecessors were the ground based DECCA, LORAN, GEE and Omega radio navigation systems, which used terrestrial longwave radio transmitters instead of satellites.

LORAN station Baker was a radio operations base in operation from September 1944 to July 1946.

LORAN was an American development, advancing the technology of the British GEE radio navigation system that was used early in World War II.

Examples of a one-way time transfer system are the clock on a church or town building and the ringing of their time-indication bells ; time balls, radio clock signals such as LORAN, DCF77 and MSF ; and finally the Global Positioning System which uses multiple one-way time transfers from different satellites, with positional information and other advanced means of delay compensations to allow receiver compensation of time and position information in real time.

During World War II, US Coast Guard LORAN Unit 92, a radio navigation station built in the summer and fall of 1944, and operational from mid-November 1944 until mid-May 1945, was located on Gardner Island's southeast end.

Loran-C time signals may also be used for radio clock synchronization, by augmenting their highly accurate frequency transmissions with external measurements of the offsets of LORAN navigation signals against time standards.

The laboratory went on to develop air-to-surface radar to detect submarines ; the SCR-584 radar, a fire control system ; and LORAN, a long-range radio navigation system.

It consisted of an LF LORAN receiver and data interface box / modem connected to a separate two-way radio.

The General Lighthouse Authorities for Britain and Ireland have contracted VT Communications to develop eLORAN ( enhanced LORAN ) radio navigational aid for mariners.

As was the case with LORAN C, its primary use was for ship navigation in coastal waters.

However, there have been attempts to enhance and re-popularize LORAN, mainly to serve as a backup and land-based alternative to GPS and other satellite navigation systems.

Although miles from any major body of water, Dana was ( closed in 2010 ) home to a United States Coast Guard LORAN navigation transmitter station.

* Long-range navigation ( LORAN )

The first of these hyperbolic navigation systems was the UK ' S Gee and Decca, followed by the US LORAN and LORAN-C systems.

TRANSIT had the distinct disadvantage that it generated two possible locations for any given measurements, locations that were close enough together that traditional navigation methods were not accurate to determine which of the two was the actual location ( in contrast to Gee or LORAN ).

Motorola offered a 1970s-era system based on the United States Coast Guard LORAN maritime navigation system.

In addition to computing tables of mathematical functions, the project did large computations for sciences, including the physicist Hans Bethe and did calculations for a variety of war projects including tables for the LORAN navigation system, tables for microwave radar, bombing tables, and shock wave propagation tables.

From 1945 to 1978 the U. S. Coast Guard operated a LORAN transmitting station, LORSTA Palau, as part of the worldwide LORAN navigation system.

These Fortress III ( SD ) would carry extensive array of equipment: the Monica tail-warning receiver, the Jostle VHF jammer, Airborne Grocer air-interception jammers ; Gee and LORAN for navigation and an H2S radar replacing the chin turret.

This creates an extremely maneuverable platform which, when combined with modern navigation aids such as LORAN and GPS allow the Cutter to maintain static positions.

In 1960, the Air Force proposed a radio-navigation system called MOSAIC ( MObile System for Accurate ICBM Control ) that was essentially a 3-D LORAN.

The current LORAN system has been phased out in the United States and Canada.

The original LORAN system was essentially a version of Gee using longer wavelengths for longer range.

He invented the Aberdeen Chronograph for measuring muzzle velocities, proposed the LORAN navigational system, contributed significantly ( perhaps critically, according to Luis Alvarez ) to the development of a ground-controlled approach technology for aircraft, and participated in preliminary meetings of the Manhattan Project.

The current LORAN system has been phased out in the United States and Canada.

Decca had previously sued the US government for alleged patent infringements over the LORAN C system in 1967.

The LORAN system was intended for ships but signal levels on the US east-and west-coast areas were adequate for use with receivers in automobiles.

During inclement weather or complete darkness, aircraft could still attack the trail by utilizing either MSQ-77 Combat Skyspot ( a radar-directed system ) or LORAN ( a radio-directed navigational system ).

A large part of the U. S. 160 meter band was allocated on a primary basis to the LORAN radio-navigation system that began operating in and around the 160 meter band in 1942.