For the optical fiber distributed systems, which are
using the Raman stimulated scattering for their function
the anti-Stokes part of the spectrum is the most important.
This part of spectrum changes the intensity in dependence
on temperature change along an optical fiber (Fig. 1).
Stokes part of spectrum embodies temperature
independence. The DTS systems therefore principally
work on the basis of the anti-Stokes part intensity to the
Stokes part intensity ratio [5]: