Specific theoretical predictions of the spatial variation of resonant Pc 5 pulsations have recently been presented by Walker (1980). STARE radar observations of the pulsation electric fields in the ionosphere have been successfully described in terms of a toroidal mode resonance by Walker et al. (1979). In the present paper we consider a suitable method for extracting the smaller poloidal component from the STARE data and compare the resulting amplitude and phase information with the theoretical predictions. The observed toroidal and poloidal components are found to be in reasonable agreement with Walker's predictions, which are based on the idea that these pulsations are generated by the Kelvin-Helmholz instability at the magnetopause.