This mathematics operation was originally invented to reduce spectral
noise and eliminate background effects of NIR data. From NIR technique
non-specific scattering of radiation at the surface of particles, variable
spectral path length through the sample and chemical composition of the
sample typically cause baseline shifting or tilting. The influence is
larger at longer wavelengths. Such multiplicative interference of scatter
and particle size can be eliminated or minimized by applying a standard
normal variate correction.
In addition to the standard normal variate correction very often a detrending
is applied in order to remove offset and tilting more thoroughly. Both
operations can be applied at once using the Linear least squares Baseline
Correction of the software.