Analyses of techniques for measuring DC and AC electric fields in the magnetosphere

Methods for measuring the amplitudes and directions of DC electric fields and the directions, power spectra, and dispersion relations of AC electric fields in the magnetosphere are discussed with emphasis on their applicability in various regimes of the magnetospheric plasma. The two classes of techniques that are discussed are measurement of the bulk flow of the plasma and the potential difference between pairs of separated conductors. The plasma bulk flow discussion includes measurements by ionospheric radar backscatter, whistler mode wave propagation, energetic or thermal particle trajectories, artificial ion cloud motion, probe measurements of bulk flow, vehicle wake analyses, effects of bulk flow on the coupling of antennas, and the bulk flow of an artificial electron beam.