Date: Mon, 18 Nov 2002 17:47:54 EST From: Nikita Zelensky To: Pascal.R.Willis@jpl.nasa.gov Cc: jean-paul.berthias@cnes.fr, ries@csr.utexas.edu, bjh@cobra.jpl.nasa.gov, Yoaz.Bar-Sever@jpl.nasa.gov, sluthcke@xyz.gsfc.nasa.gov, krchoi@csr.utexas.edu, feissel@ensg.ign.fr, nzelensk@geodesy.gsfc.nasa.gov Subject: Re: DORIS phase center determination/ all satellites > Dear Pascal, Nov 18 '02 Using cycles 1-20 SLR+DORIS orbits, I've adjusted the DORIS phase center by combining normal equations from each 10-day arc. This is the same approach I used for estimating the LRA phase center. The data weights are SLR: 10 cm, DORIS; 2mm/s. DORIS phase offset (m) X Y Z a-priori 1.171 -0.598 +1.027 estimated (npz) 1.161 -0.592 +1.005 adjustment (npz) -0.010 +0.006 -0.022 formal sigma .002 .005 .003 estimated (Pascal) 1.154 -0.593 +0.922 adjustment (Pascal) -0.017 +0.005 -0.105 sigma .040 .036 .022 As you see we differ for the Z adjustment by 8 cm, but show similar adjustments for X and Y. Are you using DORIS-only or DORIS+GPS solutions for your estimates? Anyway, I made 4 SLR+DORIS runs to see if DORIS data fits could suggest any preference. The radial orbit rms differences are about 1 mm or less. slr rms doris rms arc/run pnts (cm) pnts mm/s z20204 a-priori offsets 3416 1.802 109423 0.388 npz doris offsets 3416 1.803 109423 0.388 pw doris offsets 3416 1.807 109423 0.392 z20602 a-priori offsets 1831 1.723 112468 0.422 npz doris offsets 1831 1.724 112468 0.422 pw doris offsets 1831 1.733 112468 0.424 Best regards, Nikita