Saturday 19 December 2015

ADS-B to enable global flight tracking


One of the things that the World Radio Conference 2015 (WRC-15) enabled was to provide a universal spectrum allocation for flight tracking. What this means in simple terms is that once completely implemented, flights will hopefully no longer be lost, like MH370. It will now be possible to accurately track flights with satellites across nearly 100% of the globe, up from 30% today, by 2018.

To make you better understand this, see this video below:


Automatic Dependent Surveillance (ADS) is a surveillance technique in which aircraft automatically provide, via a data link, data derived from on-board navigation and position-fixing systems, including aircraft identification, four-dimensional position and additional data as appropriate. ADS data is displayed to the controller on a screen that replicates a radar screen. ICAO Doc 4444 PANS-ATM notes that air traffic control service, may be predicated on the use of ADS provided that identification of the aircraft involved is unambiguously established. Two main versions of ADS are currently in use:

  • Automatic Dependent Surveillance-Broadcast (ADS-B) is a function on an aircraft or surface vehicle that broadcasts position, altitude, vector and other information for use by other aircraft, vehicles and by ground facilities. It has become the main application of the ADS principle.
  • Automatic Dependent Surveillance-Contract (ADS-C) functions similarly to ADS-B but the data is transmitted based on an explicit contract between an ANSP and an aircraft. This contract may be a demand contract, a periodic contract, an event contract and/or an emergency contract. ADS-C is most often employed in the provision of ATS over transcontinental or transoceanic areas which see relatively low traffic levels. 

The ITU press release on this topic:

The frequency band 1087.7-1092.3 MHz has been allocated to the aeronautical mobile-satellite service (Earth-to-space) for reception by space stations of Automatic Dependent Surveillance-Broadcast (ADS-B) emissions from aircraft transmitters.

The frequency band 1087.7-1092.3 MHz is currently being utilized for the transmission of ADS-B signals from aircraft to terrestrial stations within line-of-sight. The World Radiocommunication Conference (WRC-15) has now allocated this frequency band in the Earth-to-space direction to enable transmissions from aircraft to satellites. This extends ADS-B signals beyond line-of-sight to facilitate reporting the position of aircraft equipped with ADS-B anywhere in the world, including oceanic, polar and other remote areas.

WRC-15 recognized that as the standards and recommended practices (SARP) for systems enabling position determination and tracking of aircraft are developed by the International Civil Aviation Organization (ICAO), the performance criteria for satellite reception of ADS-B signals will also need to be addressed by ICAO.

This agreement follows the disappearance and tragic loss of Malaysian Airlines Flight MH370 in March 2014 with 239 people on board, which spurred worldwide discussions on global flight tracking and the need for coordinated action by ITU and other relevant organizations.

For more details see: globalflightsafety.org

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