Date: Fri, 15 Nov 2002 10:14:34 -0800
From: Pascal Willis
To: jean-paul.berthias@cnes.fr
Cc: "John C. Ries" ,
Bruce J Haines ,
Yoaz Bar-Sever ,
nzelensk@geodesy.gsfc.nasa.gov, sluthcke@xyz.gsfc.nasa.gov,
krchoi@csr.utexas.edu, Martine Feissel
Subject: Re: DORIS phase center determination/ all satellites
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