ENVISAT RA-2 S-band Anomaly: Detection and Waveforms Reconstruction
Annalisa Martini(1) , Pierre Femenias(2) , Maria Pilar Milagro Perez(1) , and Giovanni Alberti(3)
Via Sciadonna, 24,
00044 Frascati, Rome,
(2) ESA-ESRIN, Via G. Galilei, 00044 Frascati, Rome, Italy
(3) CORISTA, Viale Kennedy, 5, 80125 Naples, Italy
As widely known the ENVISAT RA-2 data are affected by the so-called “S-Band anomaly” discovered in the early days of the Commissioning Phase. It consists in the accumulation of the S-Band echo waveforms that starts, apparently randomly, after an instrument Acquisition phase.
Investigation is on going to try and find the instrumental cause of this behaviour but in the meantime the data affected by this anomaly are completely unusable. For this reason the need has arisen for the users to be able to detect the anomalous data and eventually reconstruct a usable signal from them.
This paper describes the algorithm developed for the L1b processor that allows to set a flag identifying the data affected by the “S-Band anomaly” and reconstruct normal echo waveforms to be then ingested in the nominal re-tracking procedure at L2. It presents also the results obtained after the implementation in the L1b reference processor.