BD - you should know better!!
NATS doesn't give out the positions of the radar sites to anyone without a legitimate regulatory, security or safety reason. A FOIA request I suspect is pointless as NATS is a commercial company, not a government agency.
I would also suggest monitoring NATS transmissions for purposes they are not intended and using them for other applications, whether radar or voice, is probably not legal. See the sticky on the Main ATC front page
http://www.pprune.org/atc-issues/206...tions-law.html
Given that Mode A/C only radars have to be turned off by the end of 2011 in the UK (be interesting to see how the CAA make that happen given UK MoD are massively behind), any system relying on Mode A/C is probably going to be of diminishing use.
But good luck
RS