Artifacts with uneven sampling of red noise.
The vast majority of sampling systems operate in a standard way: at each tick of a fixed-frequency master clock a digitizer reads out a voltage that corresponds to the value of some physical quantity and translates it into a bit pattern that is either transmitted, stored, or processed right away. Thus signal sampling at evenly spaced time intervals is the rule: however, this is not always the case, and uneven sampling is sometimes unavoidable. While periodic or quasiperiodic uneven sampling of a deterministic signal can reasonably be expected to produce artifacts, it is much less obvious that the same happens with noise: here I show that this is indeed the case only for long-memory noise processes, i.e., power-law noises 1f;{alpha} with alpha>2 . The resulting artifacts are usually a nuisance although they can be eliminated with a proper processing of the signal samples, but they could also be turned to advantage and used to encode information.
Milotti
Edoardo
E
Dipartimento di Fisica, Università di Trieste and INFN-Sezione di Trieste Via Valerio, 2-I-34127 Trieste, Italy. milotti@ts.infn.it