Salute!
Dave! You can get a fairly accurate AoA by comparing the inertial velocity vector with the chord of the wing.
I use "body" coordinates. So if my flight path vector is "x" degrees below/above the wing/fuselage reference line, then that is my AoA. Might have some very small corrections for yaw, and the Earth ellipsoid and such,, but the basic calculation is where you are pointed and where the wing is pointed, right?
Gums suggests....