
Uncertainty in Phase Measurements ◾ 313
TABLE9.4 Summary of Contributions to the Phase Measurement Uncertainty uFF of
a Four-Frame, 8-Bit Algorithm, Keeping a Laser Interferometer in Mind
Component f
Uncertainty
Value u(f)
Phase Variance for N = 4,
Value
(,)
(mrad
2
)
Electronic noise u
el.noise
= 1.5 GL
(type A)
Γ
(, .)
2
2
.
2
2
uelnoise
u
S
FF
el noise
Equation (9.21)
275
Digitization noise S
LSB
= 1 GL per
denition
(type B)
φ=
Γ
(, )
24
2
2
2
uLSB
S
S
FF
LSB
Equation (9.21)
10
Background
uctuations
a
S
background
= 1.2
GL (type B)
Γ
(, )
2
2
2
ubackground
S
S
FF
background
Equation (9.21)
200
Shot noise
b
S
Γ
= 4,000 cnt
(type B)
φ=
ν
Γ
(, )
2[cnt]
2
ushot
S
FF
Equation (9.25)
250 ...