Background is Salisbury Plain, not Canada

but the sand/green colour scheme is the one used at BATUS.
EDIT: Probably better expressed as 'like the one used at BATUS' as it doesn't have the white V-shaped '45' on the turret used at BATUS to indicate the firing arc of the tank. The MOD photo database has some pics of the first demonstration of the Challenger 2 from 1999 in the same scheme, and also with the 'Chinese Eye' just about visible on the lower corner of the turret side too, as in photo at the start of this thread.
David