November 1980 | NTIA Technical Report TR-80-53

Evaluation of Discrete Address Beacon Systems (DABS) EMC

Robert M. Pratt; Jay S. Levy


The FAA is currently developing the Discrete Address Beacon System (DABS) as an evolutionary upgrading of the Air Traffic Control Radar Beacon System (ATCRBS). Questions have been raised regarding the Electromagnetic Compatibility (EMC) of ATCRBS and DABS because of their common channel usage. The committee on Science and Technology, U.S. House of Representatives, requested that the National Telecommunications and Information Administration (NTIA) review DABS as a radio telecommunication system giving particular attention to potential interference problems.

The EMC of DABS with operational and firmly planned systems in the 960-1215 MHz band was investigated. This was accomplished by evaluating FAA theoretical calculation, measurement, and simulation results, and performing an independent analysis through theoretical calculations and computer simulations.

It was concluded that replacing FAA ATCRBS ground sensors with DABS sensors, operating according to FAA specified scenarios, will not reduce the performance of the remaining ATCRBS sensors or the DABS sensors. The compatibility of DABS with TACAN/DME, MSL/DME, and BCAS is operationally and technically manageable. The compatibility of the ATCRBS IFF Mark XII System (AIMS) and DABS is being addressed in a joint FAA and DoD EMC study.

Keywords: electromagnetic compatibility (EMC); Air Traffic Control Radar Beacon System (ATCRBS); Discrete Address Beacon System (DABS); transponder suppression; fruit

To request a reprint of this report, contact:

Ed Drocella, Chief,
Spectrum Engineering and Analysis Division
Office of Spectrum Management
National Telecommunications and Information Administration
(202) 482-1652

Disclaimer: Certain commercial equipment, components, and software may be identified in this report to specify adequately the technical aspects of the reported results. In no case does such identification imply recommendation or endorsement by the National Telecommunications and Information Administration, nor does it imply that the equipment or software identified is necessarily the best available for the particular application or uses.

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