Beobachthung der Brillouin-Instabilität in der Ionosphäre

Abstract

Observations of weak stimulated Brillouin scattering with the 50 MHz incoherente scatter radar at Jicamarca are described. The non-linear interaction uf the upgoing radar wave with the downcoming waves, incoherently backscattered fromm greater heights, causes an asymmetry in the incoherent "ion" backscatter spectrum. For a given antenna aperture this asymmetry increases with increasing power and decreasing frequency of the rdar. The theoretically predicted effect was unambiguuosly verified, using 3 msec pulses and long integration time. Model calculations show good agreement with the observations.