Alerting system for interrogator code conflicts

Romanian air navigation service provider deploys DFS technology

10.12.2015.- The Romanian Air Traffic Services Administration (ROMATSA) has put the Mode S Interrogator Code Conflict Alerter (MICCA) into operation. The application was developed by the German air navigation service provider (ANSP) DFS Deutsche Flugsicherung to identify interrogator code conflicts of Mode S radar stations. Such conflicts may result in aircraft not being fully detected by one or more Mode S sensors.

MICCA allows system monitoring staff to simultaneously overview interrogator code conflicts at all Mode S facilities, to quickly identify affected sensors and to analyse the conflicts. Reconfiguring the affected radar station is one of the possible solutions to such a problem.

This alerting system can process live radar data from up to 32 Mode S radar stations and displays target acquisition problems graphically in real time. For example, the number of conflicts for each Mode S sensor can be represented on a time axis. Another feature is the ability to show where aircraft experienced a delay in radar detection or where they were not detected at all. As soon as specific adjustable thresholds are reached, the system sets off a visual and audible alert.

DFS has been using this in-house development to monitor Mode S facilities since 2010. The Latvian ANSP Latvijas Gaisa Satiksme (LGS) has employed this DFS tool since 2013.

A European Commission regulation has been in place since 2009 that requires Mode S operators to implement monitoring means to detect interrogator code conflicts (Regulation 262/2009, Article 7). 

Press contact:

DFS Deutsche Flugsicherung GmbH
Nanda Geelvink, Telephone: +49 (0) 6103 / 707 - 4164  E-mail:

Andra Meheş, Telephone: +40 21 2083216, E-mail:

DFS Deutsche Flugsicherung GmbH
, the German air navigation service provider, is a State-owned company under private law with 5,750 employees as at 30 June 2015. DFS ensures the safe and punctual flow of air traffic over Germany. Around 2,000 air traffic controllers guide up to 10,000 flights in German airspace every day, and about three million movements every year. This makes Germany the country with the highest traffic volume in Europe. The company operates control centres in Langen, Bremen, Karlsruhe and Munich as well as 16 control towers at international airports in Germany. In addition, DFS is represented at the EUROCONTROL Control Centre in Maastricht, the Netherlands. Additional areas of activity include consulting, provided by the Aeronautical Solutions division, and aeronautical data, grouped in the Aeronautical Information Management division.

RA ROMATSA is organised as a self-financing public company, being certified and designated as air navigation services provider, including air traffic services, aeronautical communication services, navigation and surveillance services in the aeronautical field, aeronautical meteorological services, aeronautical information services, as well as coordination of the search and rescue missions in FIR BUCHAREST. In addition to its basic activities, ROMATSA also has the right to perform consulting activities and to provide services in its field of activity, as well as research-development activities, including the manufacturing and trading of products specific to the air traffic management field, by its own forces or in partnership with the internal or external economic entities, as well as to perform its own transport activities, as per the legislation in force.