ASTERIX CAT-240

Owned by Charlotte Dakin-Norris, created
Last updated: Nov 14, 2022
2 min read

Introduction

EUROCONTROL is a pan-European, civil-military organisation established to support European aviation operations to improve safety, security, efficiency and effectiveness.

ASTERIX (All Purpose STructured Eurocontrol suRveillance Information EXchange) refers to a range of protocols for standardised information exchange between aviation systems. Category 240 (CAT-240) describes an open standard for the transmission of rotating radar video.

The ability to support ASTERIX CAT-240 allows customers to receive raw radar data without requiring Witness tools or a Navtech-supplied client library.

The CAT-240 standard is a way of exchanging radar video between a source of data and one or more destinations.

For customers and integrators intending to use ASTERIX CAT-240, the documents assume a reasonable working knowledge of UDP network communication. They are targeted at technical teams, typically with software development skills, who are integrating the output from a radar into external systems.

Contents

Overview

Navtech radars now have the capability to produce FFT (video) output in one of two formats:

  • Navtech proprietary format (Colossus).

  • ASTERIX Category 240 (CAT-240).

The CAT-240 standard allows some level of flexibility, to allow the data format to be adapted to meet the requirements of a particular application.

The Navtech-specific implementation, including specific configuration and extensions, is documented here: https://navtechradar.atlassian.net/wiki/spaces/PROD/pages/2421260375.

Network Configuration for Output Formats

The default Navtech (Colossus) data output format is a TCP-based protocol, and each azimuth is sent as a single message. Client applications are required to connect to the radar’s IP address and Data Distribution port.

ASTERIX CAT-240 does not specify a transport protocol as part of the standard. Typically, CAT-240 data is provided over UDP. The Navtech implementation can either unicast FFT (video) data to a specific IP address and port or, if supported by the system’s network configuration, multicast to a group IP address.

For the CAT-240 protocol, each azimuth of FFT data may be sent as multiple messages (see Max Packet Size in the https://navtechradar.atlassian.net/wiki/spaces/PROD/pages/2410283009/ASTERIX+CAT-240#Data-Output-Settings below for more detail).

It is the client application’s responsibility to re-combine messages into a single azimuth.

Changing the Radar Output Format

The radar output can be switched between the Navtech (Colossus) format and CAT-240 format via the Vertex user interface. Please refer to https://navtechradar.atlassian.net/wiki/spaces/PROD/pages/2269741293 for further information.

CAT-240 Output Example

Below is an example of the CAT-240 output:

Please note that CAT-240 FFT (video) data is not contoured.