I am disturbed at the information the media are getting from senior ministers, and from unnamed or non-official sources, claiming great difficulties in detecting wooden boats moving in stormy weather across large areas of ocean.

An impression is being created that Australia's $1800 million  long-range radar detection system covering Australia's northern maritime approaches, JORN -- a crucial asset in the defence of Australia against maritime or air intrusions of any kind, including terrorism -- is unreliable at such times. This might be politically convenient in the Christmas Island tragedy context, but it is not sustained by a simple study of publicly accessible facts. See the Google Wikipedia entry on radar, a detailed technical article, and the Department of Defence DMO and Wikipedia articles on JORN.

JORN is a long-distance all-weather radar system: one of many such around the world. JORN is highly admired internationally as one of the most powerful of these systems. Prime Minister Julia Gillard and and Home Affairs Minister Brendan O'Connor have implied in the past 24 hours that bad weather around Christmas Island "limits" the ability of radar to detect a wooden boat (Gillard), which is "nigh on impossible" (O'Connor). They have not said categorically that this particular boat was not detected by JORN. They have said it was not "tracked", whatever that might mean. They have stressed the local bad weather around Christmas Island at the time. But this is irrelevant to JORN, which is a long-distance system designed to detect and maintain coverage of  incoming boats as early as from the time they leave shore in Indonesia, over the duration and distance of the voyage (480 kilometres, average voyage time up to 36 hours). The task is eased because the boats are funnelling into two point destinations, Christmas and Ashmore islands.