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Air Traffic Control System
Published in Milica Kalić, Slavica Dožić, Danica Babić, Introduction to the Air Transport System, 2022
Milica Kalić, Slavica Dožić, Danica Babić
VOR is the standard air navigational system for aircraft that emits specific signals, the so-called radials, enabling them to find their position and stay on course. Each radial has a numerical value, which determines the angle position of the aircraft relative to the VOR. A VOR ground station does not measure the distance of the aircraft from this device. Typically, to measure the distance as well, a DME navigation device is installed in addition to the VOR device. With these two devices, used as route fixes within high or low airspace, each aircraft can perform its flight as planned, along the entire route. It is also possible to place PSR/SSR radars along the route (usually at the top of a mountain along the route) to allow flight surveillance during a cruise from the area control room.
Overview of GNSS
Published in Basudeb Bhatta, Global Navigation Satellite Systems, 2021
The next major advancement in radio navigation system was the use of two signals that varied not in sound, but in phase. The VHF Omnidirectional Range (VOR), is a type of radio navigation system for aircraft. This system was designed to broadcast a very high frequency (VHF, ranging from 108.0 MHz to 117.95 MHz) radio composite signal. The concept of VOR is rather complicated and beyond the scope of this book to discuss. However, in VOR, a single master signal was sent out continually from the station, and a highly directional second signal was sent out that varies in phase 30 times a second compared to the master (refer to Chapter 4, Section 4.7 for details on phase difference). This signal was timed so that the phase varies as the secondary antenna spins, such that when the antenna was at 90 degrees from the north, the signal was 90 degrees out of phase of the master. By comparing the phase of the secondary signal to the master, the angle could be determined without any physical motion in the receiver. This angle was then displayed in the cockpit of the aircraft, and could be used to take a fix just like the earlier RDF systems. This system was, in theory, easier to use and more accurate (Clausing 2006).
VHF omnidirectional range
Published in Mike Tooley, David Wyatt, Aircraft Communications and Navigation Systems, 2017
VOR is a short/medium -range navigation system operating in the 108–117.95 MHz range of frequencies. This means that the radio waves are now propagated as space waves. The problems that were encountered with ground and sky waves in the LF and MF ranges are no longer present with a VHF system. VOR navigation aids are identified by unique three-letter codes (derived from their name, e.g. London VOR is called LON, Dover VOR is called DVR, etc.). The code is modulated onto the carrier wave as a 1020 Hz tone that the crew can listen to as a Morse code signal. Some VOR navigation aids have an automatic voice identification announcement that provides the name of the station; this alternates with the Morse code signal. The location of the VOR navigation aids (specified by latitude and longitude), together with their carrier wave frequencies, is provided on navigation charts as with ADF.
Reference trajectory-based coverage analysis method in three-dimensional space for multi-radio integrated navigation systems
Published in International Journal of Image and Data Fusion, 2020
Jae Hoon Son, Sang Heon Oh, Dong-Hwan Hwang
A research on the multi-radio integrated navigation system has been performed in Korea, in which GPS is integrated with ground-based radio navigation systems such as DME, eLoran, Loran-C, and VOR, KNSS (Korean Navigation Satellite System), and Pseudo-lite (Son et al. 2019a, 2019b). KNSS is a Korean regional navigation system and will be deployed in the near future.