Fourier-series drift correction in periodic crosscorrelation schemes

It has recently been shown that polynomial-type output drift may be exactly compensated, up to the rth order, by crosscorrelating over r + 2 half periods of a periodic sequence of inverse-repeat form, where binomially distributed weights are associated with each half period. It is pointed out that the a.c. components of a Fourier-series expansion of output drift may be exactly compensated up to the qth harmonic by crosscorrelating over q + 1 periods of a periodic sequence (not necessarily of inverse-repeat form), where uniformly distributed weights are associated with each period. If the sequence is of inverse-repeat form, the d.c. component is also compensated.