Subject: Re: DORIS phase center determination/ all satellites
From: Pascal Willis <[email-masked]>
To: [email-masked]
Cc: "John C. Ries" <[email-masked]>, Bruce J Haines <[email-masked]>, Yoaz Bar-Sever <[email-masked]>, [email-masked], [email-masked], [email-masked], Martine Feissel <[email-masked]>
Date: Fri, 15 Nov 2002 10:14:34 -0800

Hello Jean-Paul,

thanks for your message.

usually my posteriori standard deviation for the R_OFF parameter are 
around 0.9 cm for spot2, spot4 and 0.5 for spot5; 1.3 for envisat; 
1.4 for topex and 0.9 for JASON. Of course, these depends mostly on 
the weight I use for the data, as well as the a priori constraints I 
use.

The numbers I gave in my table correspond to the dispersion around 
the estimated mean (given in the table). I only use values for days 
with small a posteriori standard deviation to estimate the mean.

The factor of 2 is typical of my runs with the Gipsy/Oasis. When I 
get an posteriori standard deviations, it usually needs to be 
multiplied by 2 to obtain a more realistic value, taking into account 
possible systematic bias.

I will compare my orbits looking at the eclipses aspect that you mentioned.

Have a nice week-end
Pascal