Strong radar signals occur in the mesopause region during summer, so called polar mesospheric summer echoes (PMSE). This thesis investigates PMSE with high temporal and spatial resolution. The statistical characteristics of PMSE are examined and simulated on a sub-second level. The results allow differentiating between geophysical and instrumental effects. It was shown that PMSE scattering is almost isotropic, which is in accordance with the accepted turbulence-based PMSE theory. Furthermore, it was shown that PMSE do not fill the radar observation volume homogeneously.