1. Introduction

1.1 Overview

ATASimulator is a surveillance traffic simulator software integrated with ADS-B simulator and radar simulator, or can be called ADS-B generator and radar generator or ADS-B emulator and radar emulator, same thing with different names. Anyway, ATASimulator can worked as a surveillance traffic simulator and surveillance sensor simulator.

ATASimulator allows you to create ADS-B traffic and radar traffic simulation scenarios, add different types of flights and surveillance sensors into the scenarios.

When the simulation starts to run, it will simulate the flying of flights, and generate sensor output according to sensor characteristics.

The sensor output is in Eurocontrol ASTERIX format, which is industry de facto standard, and can be used by external tools and systems.

ATASimulator was originally designed and developed to be an useful tool to test air traffic control automation system or other similar systems.

1.2 Features

ATASimulator supports the following types of flights:

• Random Flight

A random flight will select a random route by itself in a predefined fly region, and fly in a random selected ground speed and level.

• Orbit Flight

An orbit flight will enter an orbit route around a specified center with a specified radius.

• Free Flight

A free flight will fly in the space with a starting point and specified level/speed/heading, and flight level/speed/heading could be changed manually by commands included "Flight Control" in real time.

And supports the following types of sensors:

• Radar

Radar detects aircrafts by using reflection (PSR) or transponder reply (SSR), and sends out plots and/or tracks.

• ADS-B

Automatic dependent surveillance - broadcast (ADS-B) receives broadcasts from aircraft transponder, assemble and send out target report.

During the simulation, it's possible to change the simulation speed, or pause it.

It's possible to check the output of selected sensor, in both raw format and decoded format.

2. Concepts

ATASimulator tries to simulate flights and sensors the same way they behave in real world. In one simulation scenario, there are some objects and they will interact with each other.

• Space
• Flight
• Sensor
• Time

2.1 Space

Space is a three-dimensional area where flights and sensors work in.

It is equivalent to the earth surface and the space above it. All points used in simulation must be in this space, one point can be referred as a WGS-84 coordinate (aka. longitude and latitude) plus a level.

NOTE: It is not necessary to explicitly specify something like a working area, as the whole earth surface is implied in every simulation scenario.

2.2 Flight

Flights are aircrafts fly in space.

Each flight has an internal fly model, which will control how the aircraft fly, including heading, speed, level, route, etc. Each flight will fly by its own, and can go to any point in space, it doesn't care if any sensor is "observing" it.

Currently, there are three types of fly model:

• Random Flight
• Orbit Flight
• Free Flight

2.3 Sensor

A sensor locates in space, and observes flights flying in its view.

There are different types of sensor, such as primary radar (PSR), conventional secondary radar (SSR), Mode-S secondary radar (Mode-S), automatic dependent surveillance - broadcast (ADS-B), Multilateration (MLAT), each type has its very own characteristics. ATASimulator tries to simulate the behavior of each type of sensor as in the real world.

Each sensor has a set of properties, such as location, SAC/SIC, coverage, silent cone, detection probability, so that two sensors of the same type can have a very different view of space and observes different flights.

Currently, there are two types of sensor:

• Radar
• ADS-B

Each sensor will generate standard ASTERIX output according to its observation of flights in its view, the category of ASTERIX depends on the sensor's type.

For Radar,

• Category 001/002
• Category 034/048

Some sensor like ADS-B includes a property to choose which version of ASTERIX standard will be used.

• Category 021 version 0.23
• Category 021 version 0.26
• Category 021 version 2.1 (Experimental)

2.4 Time

Time makes flights and sensors move.

There are three different clocks in the simulator:

• Simulation Clock
• Running Clock
• Real Clock