Wrong Acceleration Reference

[hnes94]

I wanted to counter check my implementation against yours (EKF). I'm confused. Looking at your documentation it rightly says g_ref is [0,0,-1]. Your implementation sets [0,0,1] in NED. This leads to entirely wrong orientation estimation. Or am I missing something here? I am also checking against a simulated ground truth (from https://github.com/Aceinna/gnss-ins-sim, adjusted to my own needs). Changing g_ref to [0,0,-1] seems to yield correct results.