Global Measurement Of Low Latitude Plasma Parameters On Board The French-Brazilian Microsatellite

The French-Brazilian microsatellite (FBM)<br>is scheduled to be launched by the end of the year<br>2002. It will be placed in a low inclination (about 6<br>degrees) equatorial circular orbit at a height of<br>700km. Among the various French and Brazilian<br>experiments, it will carry a Plasma Diagnostics<br>Package (PDP) consisting of three experiments. A<br>High Frequency Capacitance probe (HFC) to measure<br>the absolute electron density along the satellite<br>trajectory, a Langmuir Probe (LP) to measure the<br>relative variation and the spectral distribution of the<br>electron density and an Electron Temperature probe<br>(ETP) to measure the variations in the electron<br>temperature and the space potential. The main<br>objective of the PDP experiments is to make global<br>observations of the characteristic features of the low<br>latitude plasma bubbles, and thereby to study the<br>dynamic and electrodynamic processes that control<br>the generation, development and decay of the plasma<br>bubbles. These satellite observations will be<br>complemented by observation from a network of<br>ionospheric sounding equipments like Ionosondes,<br>Digisondes, Polarimeters, VHF radars operated<br>simultaneously from selected ground stations in<br>Brazil as well as in other collaborating countries.<br>Data from the PDP and the other Brazilian<br>experiments are pre-processed in the Brazilian<br>Payload Computer (BPC) before being sent to the<br>main computer on board. Data on the plasma<br>irregularities collected by the LP experiment can also<br>be pre-processed on board using an FFT algorithm to<br>reduce the data volume without losing information on<br>the spectral distribution of the plasma irregularities.