
Digital storage oscilloscopes
timebase speed is slow and n is large. To avoid this, some DSOs
switch temporarily to stable averaging whenever one of the
instrument settings is changed. Following the change, the first
sample at each point is displayed at full amplitude, and will therefore
show no signal to noise improvement. The second sample at the
point is averaged with the preceding one on a 50/50 basis, one third
of the third sample is added to two thirds of the second and so on
until after n samples the algorithm switches back to exponential
averaging. Thus stable averaging weights succeeding ...