Asterix CAT-10 Plugin

Owned by Charlotte Dakin-Norris
Last updated: Aug 20, 2024
3 min read

Introduction

Asterix CAT-10 is a network communication protocol used extensively in airports and air traffic control for passing track information. Asterix is a suite of message protocols that are used for communicating various air control information of which CAT-10 is specifically for communicating tracks.

The protocol is used over standard UDP connection. 

There are two documents that describe the protocol in detail.

The primary document; Asterix Specifications Part 1 covers the protocol, including message structure and message framing for all Asterix messages: Asterix Specifications Part 1.

The secondary document; Asterix Specifications Part 7, covers details on forming and reading a CAT-10 message: Asterix Specifications Part 7.

For customers and integrators intending to use Asterix CAT-10, 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 Witness into external systems.

Contents

Overview

Witness AdvanceGuard® supports integration with many different types of external systems through the use of plugins. These are stand-alone software libraries which are dynamically loaded by AdvanceGuard® and contain code which knows how to convert the Witness data into the required format for the external system. Navtech Radar can easily develop bespoke plugins to interface with a specific type of equipment or application. The Asterix CAT-10 plugin has been developed to provide integration to a common standard used in Airport system communication.

The plugin can be selected during setup and will automatically be installed in the correct location.

Configuring the CAT-10 Plugin in AdvanceGuard®

The CAT-10 Plugin will appear as a node under the Integration Configurations folder within the Configuration Tree. The settings can be viewed and edited by enabling the Config Function, then selecting the plugin in Integration Configurations, within the Configuration Tree. Configuration settings will then be available in the Configuration Panel. 

Plugin Enabled: Select to enable the Asterix CAT-10 Plugin.

Name: The name given to the plugin.

Identification Code: Unique number identifying the AdvanceGuard® system in an Asterix network. SIC Must be smaller or equal to 255. AdvanceGuard® cannot share a SIC with another system.

Send CAT10: If this field is selected then the system will send all confirmed tracks in Witness as CAT-10 messages to the UDP Server address.

Listen CAT10: If this field is selected then the system will listen to CAT-10 messages on the UDP server and insert any tracks identified as friendly tracks into AdvanceGuard®.

One or both of the Listen CAT10 or Send CAT10 fields should be selected.

Buffer Tracks: Buffer tracks will be sent in batches according to the Timer Interval setting.

Timer Interval (s): A timer is used to control sending status messages and cleaning up buffers in milliseconds. A CAT-10 status message is sent on this timer if Send CAT10 is enabled.

UDP Server

UDP Port: The port number used for the UDP communications.

Remote IP Address: The IP address used for clients to access the UDP data. Only Multicast IPs (starting in range 224 to 239) are supported.

Source Positions

Source positions are used to configure displacements of origins between systems. This does not need to be configured for systems who's origin coincides with the AdvanceGuard® origin.

SIC: System Identification Code - uniquely identifies each systems within the airport.

SAC: Should normally be 0 for other systems in the same airport.

X: The system origin is located east from AdvanceGuard® origin by X meters.

Y: The system origin is located north from AdvanceGuard® origin by Y meters.

Custom Specification for Data Item I010/020

Spare bits in Data Item I010/020 "Target Report Descriptor" Structure of Second Extent is re-purposed in Witness CAT-10 to enable additional classification information.

The I010/020 item will always be included in Witness CAT-10 track reports and will always include at least 3 octets - 1 octet in the standard First Part and 1 octet in a First Extent as per CAT-10 specification and 1 octet in the Second Extent with the spare bits used for Witness classification as per specification below:

Structure of Second Extent

CAT-10 Original Specification

8

7

6

5

4

3

2

1

8

7

6

5

4

3

2

1

SPI

0

0

0

0

0

0

FX

SPI: Special Position Identification

FX: Extension into next extent

Witness CAT-10 repurposed specification

8

7

6

5

4

3

2

1

8

7

6

5

4

3

2

1

SPI

Classification

FX

Classification: 6 bit unsigned integer (0-32) indicating the classification:

Bit Representation

Numeric Value

Classification

Byte Value

Bit Representation

Numeric Value

Classification

Byte Value

000001

1

Any

2

000010

2

Unclassified

4

000011

3

Person

6

000100

4

Debris

8

000101

5

Boat

10

000110

6

Vehicle

12

000111

7

Aeroplane

14

001000

8

Helicopter

16

Vehicle and Aeroplane classifications can also be obtained from the standard Target Report Descriptor First Extent as per CAT-10 specifications.

Related Information

 

Safety is everything.