Data from ionospheric rockets have been studied. The data originate in part from Greenland, supplied from the Danish Space Research Institute, and from the ROSE rocket campaing in northern Scandinavia, supplied from the Max Planck Institute in Lindau, Germany. Low frequency electrostatic oscillatons are observed in the ionospheric E-region, in altitudes of 95 - 115 km. Theis low level turbulence is generated by the Farley- Buneman instability, possibly in conjunction with oscillations driven by the diamagnetic drift at density gradients in the direction perpnedicular to the magnetic field. The characteristic properties of the fluctuations have been analyzed, such as speed and direction of propagation, together with amplitude and phase relations between the fluctuations in density and electrostatic potential. The results are important for an understanding of the saturation mechanism of the ionospheric instabilitities, and for saturated nonlinear stages of plasma instabilities in general. The investigations are continued by use of advanced methods for signal analysis.