4-66
Example shown:  fv = 20, Hz  A = 1.0 g along G,  G  = 1 x 10-9/g
0.001
0.01
0.1
1
10-9
10-10
10-11
10-12
Vibration-Induced Allan Deviation Degradation
   Vibration modulates the frequency and, thereby, degrades the short-term stability.  The typical degradation due to sinusoidal vibration varies with averaging time, as shown.  Since a full sine wave averages to zero, the degradation is zero for averaging times that are integer multiples of the period of vibration.  The peaks occur at averaging times that are odd multiples of half the period of vibration.  The y() due to a single-frequency vibration is:
y () = (A/)(v/) sin2 [(/v)],
where v is the period of vibration,  is the measurement averaging time,  is the acceleration sensitivity vector, and A is the acceleration.


J. R. Vig, C. Audoin, L. S. Cutler, M. M. Driscoll, E. P. EerNisse, R. L. Filler, R. M. Garvey, W. L. Riley, R. C. Smythe, and R. D. Weglein, "Acceleration, Vibration and Shock Effects - IEEE Standards Project P1193," Proc. 1992 IEEE Frequency Control Symposium, 763-781, 1992; also, The Effects of Acceleration on Precision Frequency Sources, U. S. Army Laboratory Command Research and Development Technical Report SLCET-TR-91-3, March 1991, AD-A235470.