ADS-B

What is this?

Automatic dependent surveillance – broadcast (ADS–B) is a surveillance technology in which an aircraft determines its position via satellite navigation and periodically broadcasts it, enabling it to be tracked. The information can be received by air traffic control ground stations as a replacement for secondary radar. It can also be received by other aircraft to provide situational awareness and allow self separation.

ADS–B is "automatic" in that it requires no pilot or external input. It is "dependent" in that it depends on data from the aircraft's navigation system.

ADS-B periodically broadcasts information about each aircraft, such as identification, current position, altitude, and velocity, through an onboard transmitter. ADS-B provides air traffic controllers with real-time position information that is, in most cases, more accurate than the information available with current radar-based systems. With more accurate information, ATC will be able to position and separate aircraft with improved precision and timing.

More information about ADS-B could be accessed from Wikipedia.

How is work?

The ADS-B in AstSimulator is an emulator of real world 1090ES ADS-B receiver.

It is installed in a location in the surface of simulation space, and receives broadcasts from flights in its coverage view. Then it will assemble received information and send it out in standard ASTERIX catetory 21 messages.

External system could treate it as an ordinary ADS-B station, and receive its data of simulated flights.

In real world, different ADS-B station vendors use different versions of ASTERIX catetory 21 formats, the simulated ADS-B supports three most commonly used ones, which are:

  • Category 21 version 0.23
  • Category 21 version 0.26
  • Category 21 version 2.x

Once an ADS-B is created in simulation scenario, it is "installed" in the location specified in its parameter. An ADS-B can be "installed" in any where in the space, it doesn't have to be close to the flights.

And of course, just like in real world, an ADS-B can only "see" flights in its coverage, so you can not assume all simulated flights can be included in one ADS-B's output.

Create ADS-B Ground Station

Following are the steps to create ADS-B station.

  • Step 1

    Man menu -> Simulation -> Sensor -> Create ADS-B;

    Or Main Toolbar -> ADS-B.

    Open ADS-B Ground Station Window.

  • Step 2

    Click Create to create an ADS-B ground station.

  • Step 3

    In Main Window, switch to Sensor List View, check ADS-B ground station is created.

Here is a sample of ADS-B Window.

adsb_window.png
ADS-B Ground Station Window
And the meaning of each parameter is listed below.

Parameter Description Format Example Note
Name Name of ADS-B ground station Free text My ADS-B
Model Model of ADS-B SinoATC 1090ES ADS-B Receiver Model is used to emulate product characteristic from different vendors.
SAC/SIC SAC and SIC code [0-9]{1,3} 197 Range 0 - 255. Each sensor must have a unique SAC/SIC in one simulation scenario
Coverage Minimum and maximum coverage [0-9]{1,3} 250
Refresh Period Period to update all flights in its view [0-9]{1,2} 2 Range 1 - 10
Output Format The format that will be used to encode ASTERIX message CAT021 v0.26
Channel If output channel is activated If both channels are deactivated, no message will be transmitted even there are flights in ADS-B’s view
Multicast Address IP address of multicast group 230.230.230.1 Must be a valid multicast address
Port Port number 52001 Range 1 - 65535

After clicking the Create button, system will check all parameters, if any error is detected, an error message will be shown.

adsb_window_errormsg.png
Error Message