Michele Maris (INAF-Osservatorio Astronomico Trieste), M.Bersanelli (Milano University, Physics Department), A.Gregorio (Trieste Univ. Physics Department), S,Galeotta (INAF-OATS), M.Frailis (INAF-OATS), R.Leonardi (ESA), R.Mandolesi (INAF-IASF/BO), D.Mennella (INAF-OATS), M.Miccolis (ESO), N.Morriset(Geneva Observatory), F.Pasian(INAF-OATS), D.Tavagnacco(INAF-OATS), R.Rholf(Geneva Observatory), L.Terenzi(INAF-IASF/BO), M.Tomasi(Milano University, Physics Department), M.Turler(Geneva Observatory), A.Zacchei(INAF-OATS) (the PLANCK/LFI collaboration)
he Low Frequency Instrument (LFI) onboard the ESA Planck mission requires a constant monitoring of its raw data scientific output in
order to discover anomalies in the instrument and plan proper actions, both at level of instrument and data reduction pipeline.
The strict margins in the bandwidth available for delivery of scientific telemetry at ground coupled with the limits in the budget
allowed data degradation asks for a fine tuning of the data compression pipeline. This is one of the most critical steps of the onboard
processing of raw data, in fact any anomaly in one of the 44 detectors composing the Planck/LFI, could produce a failure of the data compressor causing a significant data loss. Data can be loosed both because the data compressor can not be able to achieve
the required compression rate, forcing the onboard software to stop the acquisition from that detector to prevent saturation of the bandwidth limits, or because the preprocessing pipeline could result in the production unrecoverable data.
This contribution illustrates the software and the methods implemented in the LFI Data Processing Center to allow automated
discovery of anomalies on raw data as soon as they are downloaded from the spacecraft, the characterization of data compressor
performances, and the generation of automated alarms. In addition we present some preliminary result on the onboard compressor
performances which is based on a novel scheme never used before in flight.
Paper ID: P092