magnetic field like maybe have some magnets on your system where you have some high currents that induce magnetic fields then it might perturb those measurements and not really get the earth magnetic field but something else are you flying near a power line or something it might perturb the measurements you're getting dynamics there is noise from the wind there's unball dynamics and engine in the servo motors and in the blades of the helicopter so overall we don't really have access to state directly but we have things that relate pretty