Australia's Jindalee Operational Radar Network (JORN) comprises three Over-The-Horizon Radar (OTHR) systems and is part of a layered surveillance network that provides coverage of Australia's northern approaches.
JORN provides wide-area surveillance at ranges of 1000 to 3000 kilometres from the radar sites, and is used to monitor the air and sea in support of Australia's national surveillance effort.
JORN was designed to detect air targets the same size as a BAE Hawk-127 aircraft or larger, and objects on the surface of the water the same size as an Armidale Class Patrol Boat (56.8 m long) or larger.
The extent of JORN coverage and system performance is highly variable and depends on the state of the ionosphere (a layer of the Earth's atmosphere), environmental conditions, and an object's size and construction.
JORN's ability to detect small wooden vessels is highly unlikely given their typical size, construction, and speed.