the truth
tilt θ
30°
noise σ
1% g
this sample
a
x
, a
y
0
0
m s
−2
estimate
θ̂
error
rms, 100 samples
arcsin(a
x
/g)
0
0
0
atan2(a
x
, a
y
)
0
0
0
pause
clear rms
true sensor
one axis, arcsin
both axes, atan2