****************************************************************************** dorismail 25-Mar-2011 13:19:29 Message No 0741 ****************************************************************************** Author: Pascal Willis Subject: DORIS data reprocessing at IGN --Apple-Mail-104-629416001 >=20 > Dear colleagues, >=20 > following my latest DORISMail (#0736) on March 4, 2011, I now confirmed t= hat all recent DORIS data were reprocessed at IGN since mid 2008 and that t= he new results (SINEX, STCD, geocenter, EOPs) are now available at both IGN= and CDDIS data centers. See below for details. >=20 > The bad news is that, the SPOT-5 DORIS data are effectively affected by t= he SAA effects, as recently discussed by Stepanek et al., 2010 in the artic= le below: >=20 > Stepanek, P.; Dousa, J.; Filler, V.; Hugentobler, U., 2010. DORIS data an= alysis at Geodetic Observatory Pecny using single-satellite and multi-satel= lite geodetic solutions, in DORIS Special Issue: Precise Orbit Determinatio= n and Applications to the Earth Sciences, P. Willis (Ed.), ADVANCES IN SPAC= E RESEARCH, 46(12):1578-1592, DOI: 10.1016/j.asr.2010.04.015 >=20 > This means that I now need to reprocess DORIS data from mid 2002 to mid 2= 008 to take care of this problem. >=20 > Finally, I will now resume our automated DORIS data processing at IGN. Ne= w weekly solutions should be submitted Today or early Tomorrow for more dat= a in 2011. >=20 > Best regards > Pascal >=20 > NB: the following article is suggested for citation purposes, when using = these DORIS/IGN results >=20 > Willis, P.; Boucher, C.; Fagard, H.; Garayt, B.; Gobinddass, M.L., 2010. = Contributions of the French Institut Geographique National (IGN) to the Int= ernational DORIS Service, in DORIS Special Issue: Scientific Applications i= n Geodesy and Geodynamics, P. Willis (Ed.), ADVANCES IN SPACE RESEARCH, 45(= 12):1470-1480, DOI: 10.1016/j.asr.2009.09.019 >=20 > ---------------------- >=20 > 1) recently reprocessed DORIS data >=20 > The following DORIS data were reprocessed using a more recent version of = the GISPY/OASIS sofware package from JPL (goa-test-2011.03.17b) >=20 > weeks: 736-738 =3D 13-FEB-1994 to 06-MAR-1994 > new SPOT3 data available at CDDIS > NB: see DORISMail #0735 from Carey Noll >=20 > weeks: 955-995 =3D 26-APR-1998 to 06-FEB 1999 > corrected SPOT4 data files from CNES > NB: see DORISMail #0735 from Carey Noll and also the following article > Willis, P; Berthias, J-P; Bar-Sever, YE. 2006. Systematic errors in the Z= -geocenter derived using satellite tracking data, A case study from SPOT-4 = DORIS data in 1998, JOURNAL OF GEODESY 79(10-11):567-572, DOI: 10.1007/s001= 90-005-0013-9 >=20 > weeks 1124-1131 =3D 22-JUL-2001 to 15-SEP-2001 > new SPOT4 data available at CDDIS > NB: see DORISMail #0735 from Carey Noll >=20 > weeks 1487-1619 =3D 06-JUL-2008 to 22-JAN-2011 > reprocessing using now Jason-2 data (since 12-JUL-2008) and Cryosat-2 da= ta (since 30-MAY-2010) >=20 > This version of the GOA software package allows Jason-2 and Cryosat-2 DOR= IS data processing, solves a bug related to Earth orientation, uses more re= cent models (IERS10 for pole tide and IAU06 for precession and nutation) an= d also removes DORIS data from SPOT-5 in the Southa Atlantic Anomaly region= (currently Kourou, Arequipa, Santa Cruz and Cachoeria =3D KRUA, KRUB, SCRB= , AREA, AREB, ARFB, CACB, CADB) >=20 > More information on SAA effect on DORIS station coordinates and velocity = in >=20 > Willis, P; Haines, B; Berthias, JP; Sengenes, P; Le Mouel, JL. 2004. Beha= vior of the DORIS/Jason oscillator over the South Atlantic Anomaly. COMPTES= RENDUS GEOSCIENCE 336 (9): 839-846, DOI: 10.1016/j.crte.2004.01.004. >=20 > Lemoine, J.M.; Capdeville, H. 2006. A corrective model for Jason-1 DORIS = Doppler data in relation to the South Atlantic Anomaly, in DORIS Special Is= sue, P. Willis (Ed.), JOURNAL OF GEODESY 80(8-11):507-523, DOI: 10.1007/s00= 190-006-0068-2 >=20 > 2) SPOT-5/SAA effect >=20 > As shown in the plot below, the new recomputation now makes the DORIS-der= ived velocity or CACB and CADB compatible (no more change in velocity) and = the geodetic local tie is now compatible with the DORIS weekly results. At = least, this is one more mystery solved. >=20 > The bad new is that even the 2002 DORIS/SPOT-5 data are affected by the S= AA effect. I then now need to reprocess 2002.5 to 2008.5 DORIS data in a mu= lti-satelliet mode, rejecting stations in the SAA region for SPOT-5 (see li= st above). >=20 --------------------------------------------------------------------- Pascal Willis Institut de Physique du Globe de Paris Ph : +33-(0)1-57-27-84-81=20=20 Etudes Spatiales et Planetologie FAX: +33-(0)1-57-27-84-82 4, place Jussieu, Case 89 Em : willis@ipgp.jussieu.fr Paris 75252 Cedex 5, France http://www.ipgp.jussieu.fr/~willis ---------------------------------------------------------------------