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Van Willigen D.,Royal Institute of Navigation | Kellenbach R.,Technical University of Delft | Dekker C.,Technical University of Delft | Van Buuren W.,Portable
GPS World | Year: 2014

A new enhanced differential Loran system demonstrates 5-meter accuracy not achievable by the current DLoran system, and requires less expensive reference stations. The total position error of Loran depends on the accuracy in time of the high-power generated Loran pulses feeding the antenna, the stability of the physical phase center of the Loran transmitter antenna, stability of the tuning of the antenna circuit, the accuracy of the measured additional secondary phase factor stored in the Additional Secondary Factor (ASF) database, and the quality of the Loran receiver. ASF is the additional delay when Loran signals propagate over land with a varying conductivity. Several years ago, the General Lighthouse Authorities (GLA) of the UK and Ireland implemented Differential Loran (DLoran) in the test area around Harwich. Unfortunately, for a number of reasons it proved to be impossible to achieve absolute accuracies of better than 10 meters with DLoran. Source


Beatty C.,Royal Institute of Navigation
International Ocean Systems | Year: 2013

The article discusses the evolution of the GNSS technology. The GPS and GLONASS both provide worldwide position, navigation and timing services, with GLONASS being slightly better at very high latitudes due to the higher inclination of the satellite orbits. Since the early 1990s receivers have been available that will track both GPS and GLONASS to give composite positioning based on a mix of satellites. This has enabled use of GNSS positioning in areas where the use of one constellation alone would not give continuous navigation due to satellite obscuration. GPS has 31 satellites operational but a number of these are now reaching their end-of-life and are in need of replacement. Although development of GPS III is well under way, the US Defense budgetary strictures have caused a considerable slowdown in the enhancement program. Source


Kendal B.,Royal Institute of Navigation
Journal of Navigation | Year: 2011

In our present age, radio communication and navigational aids are taken without comment throughout the aviation industry. However, all developments must start somewhere and it is the intention of this paper to look into the earliest days of wireless and its gradual application to aviation. The first step was, as far as I can ascertain, in October 1866 when Mahlon Loomis flew a kite from a mountain top in Virginia, USA. He had fitted a copper mesh to the kite and connected this to a copper wire. Between the wire and earth he connected a galvanometer which, he noted, deflected from static electricity. On flying an identical kite at a similar height some fourteen miles away, if the copper wire were earthed, the deflection on the galvanometer changed. However, if the kite wires were of different length, this effect was not observed. For this, in 1872, he was issued with a US Patent 129971 for wireless telegraphy but, as far as we know, apart from a few fading freehand notes, (See Figure 1) no details of his apparatus survive, so it must remain a matter of conjecture what was actually achieved. © The Royal Institute of Navigation 2010. Source


Beatty C.,Royal Institute of Navigation | Beatty C.,CBI Ltd
International Ocean Systems | Year: 2014

Collin Beatty, Royal Institute of Navigation, discusses the global navigation satellite systems developed by several countries. GLONASS started its career as a military navigation system in the early 1990s, but later on was used in civilian purposes. Unfortunately, GLONASS suffered due to the decline of Soviet Union and the lack of funds to keep it running. The European Union funded its own satellite navigation system, Gallileo, which has got its first four satellites on orbit. China has also developed its own satellite systems for more global coverage. The last 12 months have seen a number of changes in available signals and services EGNOS, the European Geostationary Navigation Overlay System, has been active for several years. India's GAGAN (GPS aided geostationary augmented navigation) is working successfully for air traffic control in Indian region. Japan has developed its Quasi-Zenith satellite system to provide better coverage than GPS. Work to identify the jammers and spoofers is under serious consideration. Source

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