EDI electron time-of-flight measurements on Equator-S

Abstract. We present the first electron time-of-flight measurements obtained with the Electron Drift Instrument (EDI) on Equator-S. These measurements are made possible by amplitude-modulation and coding of the emitted electron beams and correlation with the signal from the returning electrons. The purpose of the time-of-flight measurements is twofold. First, they provide the drift velocity, and thus the electric field, when the distance the electrons drift in a gyro period becomes sufficiently large. Second, they provide the gyro time of the electrons emitted by the instrument, and thus the magnitude of the ambient magnetic field, allowing in-flight calibration of the flux-gate magnetometer with high precision. Results of both applications are discussed.

Key words. Magnetospheric physics (electric fields; plasma convection; instruments and techniques)