Subject: discussion on DORIS discontinuities (cont'd)
From: Pascal Willis <[email-masked]>
To: IDS_Analysis_Forum <[email-masked]>
Date: Thu, 12 May 2005 10:19:45 -0700

Hi Laurent,

thanks for your contribution. Here are some answers. In the plots the 
green lines correspond to changes in the satellites constellation. 
Blue corresponds to change in station acronyms. Plots are done 
directly using the stcd weekly solutions at CDDIS. In the future all 
these plots will be available on line at CDDIS and regularly updated.

EASA. 1998/02/12
I don't see a significant discontinuity in my series but as the 
Earthquake is quite close it is better to add a discontinuity there 
in the analysis and to find at the end that it is small, rather than 
ignore it in the analysis. I will add this discontinuity in my SINEX 
output as well

change of motion
FAIA end 1995 (East). It must be quite small too. I am not sure what to do
On the other hand, I now see something very strange for FAIB in the 
second part of 2002. It seems like a larger signal in latitude and 
longitude. Should we add something there? Please confirm

ROTA around 1996 (Vertical). I agree that there is something there in 
the vertical but it could be in 1996 or 1997. It is hard to say. We 
need to agree on a specific epoch.

STJB mid-2002 (North and Vertical). This is the station that I 
suggested before and for which Martine Feissel and Karine Le Bail did 
a study and concluded that there is no problem. I still think that 
there is a discontinuity in vertical and a change in latitude 
velocity around mid-2002. We could maybe put it during the DORIS data 
gap as suggested by John Ries before

  Breaks after stop and restart of emission
  KESB end 2004 (East). I agree that we could add another 
discontinuity there too for longitude. I will add one in my time 
series too.

  MARB after restart in 04/2003 (North). It seems also safe to add one 
discontinuity somwhere during the data gap.

  EVEB after restart in 06/2003 (North and East). It also seems 
reasonable to put a discontinuity during the large data gap in 2003. 
To be on the safe side, we may also add another one in 1997. The bad 
consequence is that it will loosen the velocity determination. Do you 
agree?

For KRAB, the discontiuities are small. I suggest that you had those 
discontinuities in your analysis (or that combination centers do so) 
to be on the safe side.

Best regards
Pascal
-- 
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]