36/2018

Radio direction finders ensure safety

The complete technology of the direction finder system DF-ATC-S is integrated in a box on the mast.
The complete technology of the direction finder system DF-ATC-S is integrated in a box on the mast.
In ever more densely frequented airspaces, the challenges air traffic controllers are facing are also growing. They have to coordinate more and more aircraft, and to do so they are in constant radio contact with numerous pilots. Radar systems give them an overview of the positions of all aircraft in their area of responsibility. To make it easy to identify the pilot who is speaking, a radio direction finder provides additional directional information – so the air traffic controller does not have to laboriously look for the identification on the screen. The Bavarian technology group Rohde & Schwarz has been building radio direction finders for more than 60 years and has launched a completely new, powerful and compact generation of direction finders on the market. The entire system is mounted on the antenna mast and is ready for operation in no time at all.

Radio direction finders support air traffic control at airports and checkpoints. They detect the direction to a calling aircraft and display it on the radar image. If several direction finders are used, even the position of aircraft can be determined by taking cross bearings. On the radar screen, the calling aircraft is then displayed with a marker. This makes it easy and quick to identify the calling aircraft and avoid confusions and misunderstandings. At small airports without radar, direction finders are often the only source of direction information. Here the bearings are not displayed on the radar screen, but on a supplied panel.

The evolution of direction finder technology

The first radio direction finders were installed at airports in the 1950s. Rohde & Schwarz was there from the outset and is one of the world's leading manufacturers. With the latest R&S DF-ATC-S model, the company has now launched a completely new generation of direction finders on the market. From 2- to 32-channel systems, the new family of direction finders offers suitable configurations and options for every airport and application. This also includes a mast with extensive accessories which facilitates professional installation. Open interfaces provide the bearing data in real time and optionally allow remote control of the system.

Everything in one box

The compactness and outdoor capability of the direction finder is also unique. Digital signal processing and the miniaturization of the components allow the complete system – receiver unit, DF server, air conditioning, GPS receiver and IP switch – to fit in a box on the antenna mast. There is no need to install the system in a building or shelter, as was the case with previous models. The entire system can therefore be installed and be ready for operation in just a few hours and only requires a data and power connection.

The system family offers two different DF antennas. If equipped with the compact antenna, the DF system is easy to carry and therefore well suited for transport. Thanks to its quick installation, the direction finder can also be used at temporary airfields, for example when the Bundeswehr (German Armed Forces) are setting up a landing field for a few months abroad.

Rohde & Schwarz developed the new generation of direction finders completely in-house in just two years – and was able to build on decades of experience. In doing so, the company implemented the system family in accordance with the guidelines of the ICAO and the Federal Supervisory Authority for Air Navigation Services.