All-purpose structured EUROCONTROL surveillance information exchange (ASTERIX)

The All-purpose structured EUROCONTROL surveillance information exchange (ASTERIX) is a set of documents defining the low level (“down to the bit”) implementation of a data format used for exchanging surveillance-related information and other ATM applications.


ASTERIX was designed for communication media with limited bandwidth. This is why it follows rules that enable it to transmit all the information needed, with the smallest data load possible.


The ASTERIX library has a number of Parts; each one describes a specific application.

The “Part 1” document contains the basic principles and rules to be followed when implementing ASTERIX. For everyone new to ASTERIX, Part 1 is a good starting point.

Download Part 1

“Parts 2” and higher describe how to encode data for a specific application. These parts are commonly referred to as “ASTERIX Categories”; they are available for applications in these areas:

  • 000-127: Standard Civil and Military Applications
  • 128-240: Special Civil and Military Applications
  • 241-255: Civil and Military Non-Standard Applications

The allocation of category numbers, ranging from 000 to 127, is the responsibility of the ASTERIX Maintenance Group (AMG).

Categories in the range from 128 to 240 can be allocated by national authorities. In order to allow us to maintain a full overview over existing ASTERIX categories, please notify the ASTERIX team about any category number allocated locally.

Data Categories between 241 and 255 are designed for specific users and not do not form part of the ASTERIX Standard Document. In defining these categories, please contact the ASTERIX team. Access to all currently publicly available ASTERIX categories is provided at:

, or download our List of categories and their status.

Managing ASTERIX

The development, evolution and management of ASTERIX as a whole is the responsibility of the AMG under the Surveillance Steering Group (SUR-SG). The Focal Point for all ASTERIX-related inquiries is the EUROCONTROL ASTERIX team.

Definition of new ASTERIX data categories

If there is a requirement for the definition of a new ASTERIX category (for an additional application, for instance) please contact the ASTERIX team.

Evolution of existing ASTERIX data categories

In order to ensure global interoperability, it is imperative that each implementation of a specific ASTERIX category follows the corresponding specification exactly. Uncoordinated modifications of existing categories may lead to interruptions in the transfer of operationally significant information; this should, of course, be prevented.

If there is a need to deviate from an existing category, it is mandatory to contact the ASTERIX Manager so as to find the best way of making the necessary modifications and maintaining backwards compatibility.

ASTERIX-related inquiries

For any question about ASTERIX, please contact the ASTERIX team.


Contact us for more information about ASTERIX or for requests to define new ASTERIX categories.

96, Rue de la Fusée
1130 Brussels