Date: Fri, 12 Mar 2004 14:23:43 -0800 From: Pascal Willis To: Herve Fagard Cc: Martine Feissel , Jean-Francois Cretaux , John Ries , Ramesh Govind , Adèle Guitart , Herve Fagard , Serguei Kuzin , Jean-Michel Lemoine , Jean-Jacques Valette , Jean-Paul Berthias , Pascal Willis , lebail@ensg.ign.fr, Zuheir Altamimi , Urs Hugentobler , Petr Stepanek , Jean-Pierre Granier , Gilles Tavernier Subject: STJB - data gap 2002:231-2002:259 + storm Hi Herve, following my latest email concerning a possible break in the STJB times series, John Ries was suggesting that the break (-1.7 cm in vertical) could have happened in fact during the STJB data gap ( 2002:231-2002:259 ) and not in early 2003 as I previously thought. This is a much more logical hypothesis. I checked the GECO meeting summaries and I found in the GECO #85 (2002, Sep 16) that the STJB beacon had to be reprogrammed due to a violent storm. After that event, its internal clock had also to be reset as the frequency was to far away. Here are my questions : - was this intervention only software related? button to push? Or was something done physically to the antenna, like fixing it more solidly after the storm? Anybody else I should contact about solving this issue? - is there any evidence that the storm could have damage the antenna or the place where the antenna lie on? or not? Any suggestion would be very much appreciated Pascal NB: I estimated the STJB height velocity with or without the break (during the data gap this time). With the break it went down from -10.1 mm/yr to a more reasonable -3.4 mm/yr. -- Pascal Willis Jet Propulsion Laboratory, MS 238-646 Ph : 1-818-393-4748 4800 Oak Grove Drive FAX: 1-818-393-4965 Pasadena CA 91109 Em : Pascal.R.Willis@jpl.nasa.gov