SOMARE-99: Observations of tropospheric scattering layers using multiple-frequency range imaging

Results from an experimental implementation of multiple-frequency range ima ging (RIM) are presented. The technique exploits the benefits of frequency diversity to improve range resolution of atmospheric radar systems. The the ory has been described in the literature, and simulations have proven its u sefulness. Nevertheless, experimental results have been extremely limited. Over a 5-day period in May 1999 we conducted experiments using RIM on the s ounding system (SOUSY) radar in northern Germany to observe the layered str ucture in the troposphere. The experiment is referred to as the SOUSY Multi frequency Atmospheric Radar Experiment 1999 (SOMARE-99). Estimates of range brightness produced by the RIM analysis provide insight about the layered structure of the atmosphere. The RIM results show distinct similarities to previous in situ measurements, which have shown sharp refractive index disc ontinuities to exist throughout the troposphere and stratosphere. Examples from selected time periods show layers modulated by possible short-period g ravity waves or advection of periodic structures as well as other layers wi th apparent downward motion possibly caused by the progression of a warm fr ont or large-scale subsidence.