On Thursday 13th March, the first interview in BBC's 'Inside Science' programme on Radio 4 was with Dr Matt Greaves, a Lecturer in Accident Investigation at Cranfield University, UK. The subject was "Tracking Planes" and provides a good overall assessment of what is and is not currently available. It's only 5 minutes long and is available as a podcast too.
BBC Radio 4 - Inside Science, Tracking planes; Peer review; Mega-virus; Astronaut