5 technologies applied to drones & their legal implications in 5 days. Day 2: ADS-B

Published: 17 September 2019


For those of you not from a traditional manned aviation background, ADS-B may be something unfamiliar to you. However, it’s worth being aware of this technology which is being increasingly applied to drones.

Here’s a quick run-down of this technology and some of its legal implications.

Who, what, where?

[1] ADS-B stands for Automatic Dependent Surveillance – Broadcast.

[2] It is a type of tracking system in which electronic equipment, using GPS, automatically transmits and/or receives information about an aircraft, including its location, velocity and identity, twice per second via a digital data link.

[3] There are 2 types of ADS-B: ADS-B out and ADS-B ‘in’.

[4] ADS-B ‘out’ is the transmission or broadcast of the aircraft’s details using GPS.

[5] ADS-B ‘in‘ involves the receipt of transmissions from aircraft with ADS-B ‘out’.

[6] Anyone with an ADS-B ‘in‘ receiver can collect and display the information broadcast by ADS-B ‘out’. This typically includes ADS-B ground stations which relay this information to Air Traffic Control consoles; as well as other aircraft that have ADS-B ‘in’.

[7] Airservices Australia, which Australia’s air navigation, aviation rescue and fire-fighting service, operates more than 70 ADS-B ground stations which relay the information to Air Traffic Control.

[8] An ADS-B ‘in’ system far exceeds the capabilities of the human eye to detect aircraft.

[9] Australia commissioned the world’s first continent-wide ADS-B system in 2009 and has full continental ADS-B coverage above 30,000 feet.


[10] ADS-B ‘out’ is mandatory for certain manned aircraft. The Civil Aviation Safety Authority (CASA) has published a range of regulations concerning the fitment and use of ADS-B.

[11] However, there are no mandatory requirements for ADS-B ‘in’ to be fitted to manned aircraft and no requirements for drones to have any ADS-B technology.

Relevance to drones

[12] In May 2019, DJI announced that all new DJI drone models released after 1 January 2020 that weigh more than 250 grams will include ADS-B ‘in’ technology, which they call Airsense.

[13] This ADS-B ‘in’ technology will allow the drone’s ground control station and as a result the remote pilot, to detect airplanes and helicopters who have ADS-B ‘out’. The range is further than a drone pilot can hear or see them, and displays their locations on the screen of the pilot’s remote controller and warns drone pilot if they appear to be on a collision course.

[14] ADS-B ‘in’ has been already installed in some of DJI’s high-end models like the Matrice 200 series (circa $16k) and Mavic 2 Enterprise (circa $3k). The break-through here is for the smaller drones to have this technology.

[15] To be clear, it is not a requirement for aircraft, including drones, to have ADS-B ‘in’, however it’s a positive safety initiative from DJI.

[16] Also, in the unfortunate event of an accident, the presence of otherwise of this technology could play a part in the evidence of any ensuing litigation.

[17] A final note, as ADS-B ‘in’ will only detect certain aircraft transmitting via ADS-B ‘out’, it’s always important to also maintain direct visual situational awareness of the airspace surrounding your drone.

Hope you took some value from Day 2 of our 5 day series on drone technology. A link to our Day 1 topic: Counter-drone technology, can be accessed here.

Fly Free!

The Drone Lawyer

17 September 2019