Ime-Hf Analyser for the Taranis Satellite

Abstract

International audienceThe scientific instrument IME-HF is a high frequency analyzer for the future French satellite TARANIS which is intended to study radiation originating in transient luminous events connected with lightning discharges and occurring above thunderstorms. The satellite will be launched in 2013 on a polar orbit with an altitude of 700 km. The observation of electromagnetic radiation in HF range from space will provide us with important information about lightning properties, mainly in the case of intra-cloud discharges which are difficult to detect optically. We prepare a ground-based observational campaign with an identical high frequency analyzer. After the launch of the TARANIS satellite this campaign will complement the observations from space. The analyzed frequency band is from 100 kHz to 35 MHz. Selected interesting parts of the electric field waveform (sampled at 80 MHz) will be recorded. Signal from a filter bank will be also continuously stored and analyzed to trigger the waveform capture and to obtain a map of global distribution of intensity of HF waves. The analog part of the IME-HF instrument includes amplifiers, anti-aliasing filter and the set of twelve band-pass filters with amplifiers and RMS detectors. The core of the digital part of the electronics is the FPGA (Virtex4 family), where the sampled and digitized signal is processed. We present the first results of the tests of the IME-HF analyzer, including the analyzer response to several types of artificial signals and discharges