The STARE (Scandinavian Twin Auroral Radar Experiment) and SABRE (Sweden and Britain Radar Experiment) systems have been used to estimate electric fields in the high-latitude ionosphere during a Pc 5 geomagnetic pulsation. With each coherent radar system, measurements are made over a large area (~200,000 km2) with good spatial resolution of 20¿20 km2. Combined, the systems cover a range in L value from 4.4 to 8.8. The observations were made during the local magnetic afternoon hours in the recovery phase of a magnetic storm. The period is essentially constant with latitude (geographic latitude 64.6¿--70.2¿), having a mean value of 365 s for both toroidal and poloidal components. The azimuthal wave number is large (~240, and the phase velocity is directed equatorward and westward. When mapped in a dipole field into the equatorial plane, at L=6.14, the wavelengths were found to be 9177--9585 km for both the STARE and SABRE field of view. The pulsation amplitude is <8 mV m-1. The pulsation amplitude maximizes at 69¿ geographic latitude for STARE and at 67.6¿ latitude for SABRE (corresponding geomagnetic latitude 66.4¿--66¿). The variation of azimuthal phase velocity with L resembles the gradient curvature drift of energetic hot protons. The observations are compared with the drift wave instability of compressional and shear Alfv¿n mode in a high &bgr; plasma.