Signal averaging improves signal-to-noise in OCT images:But which approach works best and when?

摘要

The high acquisition speed of state-of-the-art optical coherencetomography (OCT) enables massive signal-to-noise ratio (SNR)improvements by signal averaging. Here, we investigate the performanceof two commonly used approaches for OCT signal averaging. We presentthe theoretical SNR performance of (a) computing the average of OCTmagnitude data and (b) averaging the complex phasors, and substantiateour findings with simulations and experimentally acquired OCT data. Weshow that the achieved SNR performance strongly depends on both theSNR of the input signals and the number of averaged signals when thesignal bias caused by the noise floor is not accounted for. Thereforewe also explore the SNR for the two averaging approaches aftercorrecting for the noise bias and, provided that the phases of thephasors are accurately aligned prior to averaging, then find thatcomplex phasor averaging always leads to higher SNR than magnitudeaveraging.