feat(simulation): add sensor_adsb_sim for simulated ADS-B traffic by anilkir · Pull Request #27409 · PX4/PX4-Autopilot

anilkir · 2026-05-20T07:14:14Z

Description

This adds an ADS-B simulator with a very rudimentary multi-aircraft simulation model, similar to the implementation in ArduPilot. The module runs at 1 Hz (matching real ADS-B squitter rate) and integrates aircraft positions using a flat-earth approximation. Each aircraft is spawned at a random bearing and distance within the configured radius, flies a constant random heading and speed, and is re-spawned when it exits the radius, descends below ground, or climbs more than 1000 m above the configured altitude.

This works in POSIX SITL and SIH on real hardware.

New parameters:

SIM_ADSB_COUNT: Number of simulated aircraft (max 10)
SIM_ADSB_RADIUS: Spawn/despawn radius around ownship
SIM_ADSB_ALT: Target cruise altitude (AMSL) for simulated traffic

Known limitation: MAVLink heartbeat not simulated

A real ADS-B receiver is a MAVLink component that sends ADSB_VEHICLE messages and a HEARTBEAT message. The MAVLink module tracks that heartbeat in telemetry_status.heartbeat_type_adsb, and Commander uses it to set traffic_avoidance_system_present.

The proposed sensor_adsb_sim publishes transponder_report directly over uORB, bypassing the MAVLink receive path. As a result, traffic_avoidance_system_present is never set during simulation, even though traffic reports are flowing.

The simulation of an ADS-B receiver with a full MAVLink interface to simulate the HEARTBEAT messages as well is deferred to a follow-up.

Changelog Entry

For release notes:

Feature: ADS-B simulator
New parameters: SIM_ADSB_COUNT, SIM_ADSB_RADIUS, SIM_ADSB_ALT

Test coverage

This was tested in SITL and the ADS-B emitter positions were verified on GCS.

github-actions · 2026-05-20T07:20:58Z

🔎 FLASH Analysis

px4_fmu-v5x [Total VM Diff: 2180 byte (0.11 %)]

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    [NEW]    +276  [NEW]    +276    SensorAdsbSim::SensorAdsbSim()
    [NEW]    +260  [NEW]    +260    SensorAdsbSim::spawn_vehicle()
    [NEW]    +140  [NEW]    +140    SensorAdsbSim::~SensorAdsbSim()
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    [NEW]     +84  [NEW]     +84    SensorAdsbSim
    [NEW]     +80  [NEW]     +80    SensorAdsbSim::print_usage()
    [NEW]     +52  [NEW]     +52    SensorAdsbSim::random_float()
    [NEW]     +52  [NEW]     +52    SensorAdsbSim::updateParamsImpl()
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    [NEW]     +64  [ = ]       0    SensorAdsbSim::custom_command()
    [NEW]     +32  [ = ]       0    SensorAdsbSim::desc
    [NEW]     +48  [ = ]       0    SensorAdsbSim::init()
    [NEW]     +48  [ = ]       0    SensorAdsbSim::print_usage()
    [NEW]     +48  [ = ]       0    SensorAdsbSim::random_float()
    [NEW]     +48  [ = ]       0    SensorAdsbSim::spawn_vehicle()
    [NEW]     +48  [ = ]       0    SensorAdsbSim::task_spawn()
    [NEW]     +32  [ = ]       0    SensorAdsbSim::updateParamsImpl()
    [NEW]    +224  [ = ]       0    SensorAdsbSim::~SensorAdsbSim()
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Updated: 2026-05-21T09:41:36

Claudio-Chies

Thanks alot for takling this, this will be a huge improvement over the current implementation! added a few comments, and i would make sure to also add it to the docs, and remove the run_fake_traffic

Claudio-Chies · 2026-05-21T07:14:46Z

+      max: 100000.0
+    SIM_ADSB_ALT:
+      description:
+        short: Altitude of simulated ADSB aircraft (MSL)


thats just the start altitude of the simulated airfracts, right, i would write this more clearly

Claudio-Chies · 2026-05-21T07:29:08Z

+parameters:
+- group: Sensors
+  definitions:
+    SENS_EN_ADSBSIM:


this param is not mentioned in the PR

Claudio-Chies · 2026-05-21T08:32:52Z

+		report.icao_address  = v.icao_address;
+		report.lat           = v.lat;
+		report.lon           = v.lon;
+		report.altitude_type = 0;


i think we are simulating GPS altitude, and not Pressure adjusted altitude

report.altitude_type = 1;

feat(simulation): add sensor_adsb_sim for simulated ADS-B traffic

7f43eca

github-actions Bot added kind:feature Request or change that adds new functionality. scope:simulation SITL, Gazebo, jmavsim, lockstep, or simulated sensors. labels May 20, 2026

anilkir mentioned this pull request May 20, 2026

feat(simulation): add ADS-B failure injection to sensor_adsb_sim #27410

Draft

feat(msg): add altitude types to TransponderReport

bc1fbf2

github-actions Bot added the scope:uorb uORB messages, generated interfaces, or message translation. label May 21, 2026

Claudio-Chies reviewed May 21, 2026

View reviewed changes

fix(adsb): fix format

6619bf6

Claudio-Chies force-pushed the feat/sensor-adsb-sim branch from aa850de to 6619bf6 Compare May 21, 2026 09:36

MaEtUgR self-requested a review May 21, 2026 11:29

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feat(simulation): add sensor_adsb_sim for simulated ADS-B traffic#27409

feat(simulation): add sensor_adsb_sim for simulated ADS-B traffic#27409
anilkir wants to merge 3 commits into
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anilkir:feat/sensor-adsb-sim

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anilkir commented May 20, 2026

Description

Changelog Entry

Test coverage

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github-actions Bot commented May 20, 2026 •

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