The FAST satellite fields instrument

We describe the electric field sensors and electric and magnetic field sign al processing on the FAST (Fast Auroral SnapshoT) satellite. The FAST satel lite was designed to make high time resolution observations of particles an d electromagnetic fields in the auroral zone to study small-scale plasma in teractions in the auroral acceleration region. The DC and AC electric field s are measured with three-axis dipole antennas with 56 m, 8 m, and 5 m base lines. A three-axis flux-gate magnetometer measures the DC magnetic field a nd a three-axis search coil measures the AC magnetic field. A central signa l processing system receives all signals from the electric and magnetic fie ld sensors. Spectral coverage is from DC to similar to4 MHz. There are seve ral types of processed data. Survey data are continuous over the auroral zo ne and have full-orbit coverage for fluxgate magnetometer data. Burst data include a few minutes of a selected region of the auroral zone at the highe st time resolution. A subset of the burst data, high speed burst memory dat a, are waveform data at 2x10(6) sample s(-)1. Electric field and magnetic f ield data are primarily waveforms and power spectral density as a function of frequency and time. There are also various types of focused data process ing, including cross-spectral analysis, fine-frequency plasma wave tracking , high-frequency polarity measurement, and wave-particle correlations.