To A and C
Re: strobe detectors
As I understand it, the CAA did look into the possibility of strobe light detection equipment along with RAF. Whilst the trials were reasonably successful, it appears that production of such is not commercially viable due to their complexity.
Exact info from the AAIB website (in relation to another midair, between Tornado and C152). Section 2.2.5 at
http://www.open.gov.uk/aaib/gbpzx/gbpzx.htm#Collision