I am a massive geek that regrets every day not applying to NATS (even managed to source a copy of David Graves UK ATC book that was getting rare to find at the time ready for my application - it just sits on my shelf reminding me about my failure to apply) and have to say I find threads like this fascinating for my little geekish brain. I have three questions that have been playing on my mind for years that I wonder about:
1) I understand primary and SSR radar and I know places like Gloucester/Southend (about to change?) use primary only radar and I know unless you have SSR and a Mode C readout you won't know the height of the target but is there some sort of limit based on the radar emitter power/beam angle (I take it approach radars are angled more towards the horizon compared to enroute?) that means that contacts above xx thousand feet are not going to show? Theres a scanner video on Youtube (search southend approach, talks about RIS so I know it is not new) where some contacts are reported "unknown high speed traffic...(range/bearing)...level unknown" - could this be just as likely to be an overflying flight at FL360 in the airways as much as it could be a fast moving military A/C or will the radar not pick up contacts that high being a non-enroute radar?
2) Say you have an airways leaver going to Gloucester or Oxford and they leave airway CAS and are given some sort of TS/DS outside CAS by swanwick, I understand that part of the radar processing uses some sort of 'height filters' in the enroute sector so it does not clutter the radar with people flying over the top (?) or below. Do these filters get turned off when providing a service outside CAS and you get all primary returns and non-filtered SSR traffic to advise/deconflict with the airways leaver?
3) Do you have to be a licenced airfield to provide radar? I thought you would but it looks like Lasham (from the start of this thread) has some sort of radar...is it just a case of getting permission from Ofcom or whoever to operate in that frequency range and away you go...I always thought to provide a radar service you had to provide an ATC service and to provide ATC you needed to be licenced or am I hopelessly wrong on this one aswell.
Thanks for any answers - they will just satisfy some curiosity going around my brain!