IO - yes I agree, but the AIC has this to say
Autonomous Integrity Monitor (RAIM) availability prediction should take into account the GPS constellation predicted for the duration of the flight, NOTAM and avionics architecture
eg, Baro aiding input.
my bold.
That sort of suggests that RAIM prediction and in particular baro outages may be important to me as I am steaming down my approach.
It still leaves me worrying how and why and in what way the G1000 is interperolating its GPS information with baro information in arriving at its RAIM predictions and in what way something different is happening in the States for example.
The CAA says I must ask my qualified flight instructor - that should be an interesting conversation.
Perhaps I should ask the CAA - they obvioulsy know something I dont (which is hardly surprising) but I wish they would tell me.