Automatic dependent surveillance-broadcast

Automatic Dependent Surveillance - Broadcast (ADS -B) to German as Automatic Dependent Surveillance is a system of air traffic control to display the aircraft movements in airspace.

Function

The aircraft autonomously determine their position, for example on satellite navigation systems such as GPS with EGNOS and GLONASS. The position and other flight details such as flight number, aircraft type, time signal, speed, altitude and direction are continuously planned flight - typically once per second - omni-directional radiated at 1090 MHz. Therefore, it refers to the process as ADS-B (broadcast), more accurate than ADS-B out for output. Also possible is the shipping upon request. The system is called ADS- C (contract ) or ADS -A ( adressed ).

Flight control receives the data of all road users (as ADS-B out ) and prepares them graphically. This information will be those that are derived from ground-based radar observations, clearly superior. If the total traffic data via ADS -B ( in for input) transmitted to the aircraft, pilots and air traffic controllers have the same overview of air traffic, the so-called cockpit display of traffic information ( CDTI ). The range of the ADS-B broadcast is up to 200 nautical miles ( 370 km ) for receiving agencies on the ground.

Use

Primary ADS-B is used by air traffic control for the detection and monitoring of aircraft to improve safety by providing better information to the pilot of the aircraft environment. ADS-B caused thereby lower costs than conventional radar and increases the quality of the location of aircraft by a radar in comparison to the higher update rate. ADS-B is used today in regions where there are no nationwide radar coverage, such as Alaska or Australia. Another application is the use as a substitute for the ground radar to monitor the aircraft on the apron and taxiways of airports.

The web service Flightradar24 analyzes this data also.

In many newly delivered airliners include ADS-B transponder standard equipment.

Schedule the introduction of ADS-B

The schedule of implementation is determined by the equipment of ADS-B transponders in the aircraft, equipment costs, benefits received, and the regulations of the aviation authorities. The costs of retrofitting aircraft with ADS-B transponders is relatively low and provides a number of benefits for air traffic control and airspace users.

Short-term developments (2006-2008) in the years to ADS-B field trials will continue and retrofitted an increasing number of older commercial aircraft with ADS-B avionics.

• Sweden. The Swedish Aviation Authority is currently developing a nationwide network of 12 ground stations.

• Australia. Australia is conducting field trials in Queensland, to test the feasibility of ADS-B as an alternative to radar-based surveillance systems. It is expected to cost savings and improved safety, particularly in the areas can be achieved by the ADS-B, which are not yet completely covered by the radar.

Medium-term developments (2008-2012) In addition to the further spread of ADS-B transponders in commercial aircraft, it is expected that a larger number of ground stations will be put into operation.

Long-term effects ( from 2012)

• A nearly full equipment of fleets of airlines will allow you to enjoy the benefits of ADS-B to a greater extent.
• Through a greater accuracy of air surveillance, it could be possible to introduce lower Staffelungsminima and thereby increase the capacity of airspace.

Related systems

The voice-enabled VHF radio systems for air traffic management reach their full capacity in the near future. The European project SESAR will encounter include a selection of data-based systems. So the Traffic Alert and Collision Avoidance System could be developed. The expansion of the secondary radar by Mode S extended squitter ( ES) will not be pursued in future probably in favor of VDL Mode4 in Self Organising TDMA ( STDMA ).

Especially for the needs of small aviation (high aircraft density, frequent trajectory forecasts, cost, space and energy saving) an ADS -B concept called FLARM was implemented. It has spread rapidly worldwide since its introduction in 2004, although it is based on a proprietary wireless protocol. By the end of 2009 approximately 14,000 systems in use. However, the limited range of FLARM ( <5 km) does not allow a larger overview of the airspace. There are also ( for this reason), no ground stations that could provide an overview eg outside the space transport. FLARM is by design, a collision warning device, originally intended for gliders.

In shipping, the CDTI is, a similar system Electronic Chart Display and Information System.