Results are presented of scintillation observations made during a two and a half year period at Lerwick in the Shetland Islands using more than 19000 passes of NNSS satellites. Examples of scintillation morphology, in the region near the scintillation boundary and the F-layer trough, for both amplitude and phase are discussed using exceedence levels for the S sub 4 and sigma sub psi indices respectively. The equatorwards advancement of the ...