No. 313 Radar Station RAAF was established at Mascot in Sydney and was posted as follows during World War 2:-

RAAF Radar Station No. 313 was located at the southern end of Mornington Island in the Gulf of Carpentaria. Flying Officer R.J. Brown and 35 RAAF personnel were attached to this Radar unit. There was a small new airfield adjacent to the Radar Station for the delivery of supplies, etc.

In about November 1943 spurious radar echoes were recorded circling a section of the island about 10 - 15 miles north west of the Radar Station. An investigation to identify the aircraft proved inconclusive. On 14 January 1944 the on-duty crew at the Radar Station detected another single unidentified aircraft circling in the same area.