The Civil Aviation Safety Authority (CASA) is using drone detection equipment at major airports and events around the country to monitor drone use and enforce safety rules. Drones must not to be operated within 5.5 kilometres of a controlled aerodrome, over Sydney Harbour, or over people or populated areas such as sporting events, concerts and public gatherings.

https://www.cio.com.au/article/662173/casa-running-drone-detection-trial-major-airports-sydney-harbour/