Subject: STJB - data gap 2002:231-2002:259 + storm
From: Pascal Willis <[email-masked]>
To: Herve Fagard <[email-masked]>
Cc: Martine Feissel <[email-masked]>, Jean-Francois Cretaux <[email-masked]>, John Ries <[email-masked]>, Ramesh Govind <[email-masked]>, Ad�le Guitart <[email-masked]>, Herve Fagard <[email-masked]>, Serguei Kuzin <[email-masked]>, Jean-Michel Lemoine <[email-masked]>, Jean-Jacques Valette <[email-masked]>, Jean-Paul Berthias <[email-masked]>, Pascal Willis <[email-masked]>, [email-masked], Zuheir Altamimi <[email-masked]>, Urs Hugentobler <[email-masked]>, Petr Stepanek <[email-masked]>, Jean-
Date: Fri, 12 Mar 2004 14:23:43 -0800

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 : [email-masked]