All-purpose structured EUROCONTROL surveillance information exchange

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 is 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 consists of several parts, each of them describing the encoding of information related to 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.

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.