Originally Posted by JDiver

Read upthread, and the News thread wiki. The change of search area was deduced by new calculations involving the "pings", Doppler effect on the "pings" and recalculations of probable route and reduced range caused by higher speeds increasing fuel consumption. That's pretty much what has been announced by the Malaysian government et al.

It is highly unlikely Australian radar was able to detect a 777 1,100 mi / 1,800 km off shore. Only phased array radar like a PAVE PAWS system would be able to do that, and it would not be cost-effective for Australia to have such a system deployed on the west coast (assuming they had such).