
32
Table 6 – Mathematical expectation of calculated functions when channels "noise
floor" measuring
Number
Calculated functions
Mathematical
expectation
1
Relative frequency difference
measured in CHANNEL 1
N
c
y
1
2
Relative frequency difference
measured in CHANNEL 2
N
c
y
2
3
Sum relative frequency difference
CHANNEL 1 and CHANNEL 2
N
c
N
c
y
y
2
1
−
4
Standard deviation measured in CHANNEL 1
2
1
c
5
Standard deviation measured in CHANNEL 2
2
2
c
6
Sum standard deviation
CHANNEL 1 and CHANNEL 2
2
2
2
1
c
c
+
7
Standard cross-deviation
CHANNEL 1 and CHANNEL 2
0
8
Allan deviation measured in CHANNEL 1
2
1
c
9
Allan deviation measured in CHANNEL 2
2
2
c
10
Sum Allan deviation
CHANNEL 1 and CHANNEL 2
2
2
2
1
c
c
+
11
Allan cross-deviation
CHANNEL 1 and CHANNEL 2
0
Notes:
Formulas №№ 4, 5, 6, 8, 9, 10 give systematic error caused by channels noise;
Formulas №№ 7, 11 give non-biased estimations.
The device is considered operational if the values of the calculated statistical
functions that estimate the frequency instability do not exceed those given
in the table 2.