THE CLUSTER SPATIOTEMPORAL ANALYSIS OF FIELD FLUCTUATIONS (STAFF) EXPERIMENT

The Spatio-Temporal Analysis of Field Fluctuations (STAFF) experiment is one of five experiments which together comprise the Wave Experiment Consortium (WEC). STAFF consists of a three-axis search coil magnetom eter to measure magnetic fluctuations at frequencies up to 4 kHz, and a spectrum analyser to calculate in near-real time aboard the spacecra ft, the complete auto- and cross-spectral matrices using the three mag netic and two electric components of the electromagnetic field. The ma gnetic waveform at frequencies below either 10 Hz or 180 Hz is also tr ansmitted. The sensitivity of the search coil is adapted to the phenom ena thee be studied: the values 3 x 10(-3) nT Hz(-1/2) and 3 x 10(-5) nT Hz(-1/2) are achieved respectively at 1 Hz and 100 Hz. The dynamic range of the STAFF instruments is about 96 dB in both waveform and spe ctral power, so as to allow the study of waves near plasma boundaries. Scientific objectives of the STAFF investigations, particularly those requiring four point measurements, are discussed, Methods by which th e wave data will be characterised are described with emphasis on those specific to four-point measurements, including the use of the Field E nergy Distribution function.