Formation and migration of extrema in the angular dependency of the light-s
cattering intensity tan indicatrix), under variation of the size and the re
fractive index of a homogeneous sphere, have been studied analytically and
numerically. Approximations of Wentzel-Kramers-Brillouin (WKB), Rayleigh-Ga
ns-Debye (RGD), Fraunhofer diffraction, and anomalous diffraction (AD) have
been considered for the relative refractive index ranging from 1.025 to 1.
200. Utilization of these approximations has allowed us to reveal the gener
alized coordinates. The plot of extrema locations of the indicatrix calcula
ted from the WKB approximation with these coordinates has shown a universal
mechanism of formation of the indicatrix structure. We determined the uppe
r boundary of the angular region of Fraunhofer diffraction (FD) applicabili
ty. An analysis of the extrema has shown that locations of the different mi
nima migrate monotonically when the size of the sphere is varied. An empiri
cal equation that relates the minimum location to the sphere size has been
produced. It has been shown that the distance between minima is insensitive
to variations of the relative refractive index. The disappearance of the m
inima with an increasing relative refractive index has been discussed.