Detection and Correction of Small Abscissa Errors

The availability of quantifying procedures such as least-squares fitting and correlation makes it possible to suppress noise which occurs at spatial frequencies higher than those of the analyte signal. However, these calculations do not discriminate against low-frequency interferences, whether by random noise or other sources. One of the significant contributions to low-frequency interfering signals in Raman as well as in other types of spectroscopic measurements is uncertainty in the establishment of the abscissa position. Having found this to be a limiting factor in certain measurements, we have been interested in finding a procedure that would allow efficient recognition and correction of these errors.