This directory provides: - the corrective model of DORIS/Jason USO frequency (modele.tar.gz) - the technical note (TechnicalmemoIDS.pdf) describing the model, how to implement it in a UNIX environment, and how to use it. 1. Get the files modele.tar.gz and TechnicalmemoIDS.pdf 2. Implement the model according to the steps described in part 3 of the technical note. 3. Use the model as described in part 3 of the technical note. Remarks: Since May 3th 2012, the satellite Jason-1 has been moved to a geodetic orbit. The corrective model for Jason-1 has been updated to take into account the new orbit of Jason-1. The main change is that we cannot any more consider the Topex mean ground track (determined over a 7-year period) after the maneuvers performed to move Jason-1 on the geodetic orbit. For the new orbit, since it is drifting, we had to add another capability in the model. We can use an external orbit in a sp3 format. So, before the orbit change, we can use Topex mean ground track or sp3 orbit files, and after change only sp3 files. The new version of software is online with the following upgrades: - a new input file called « orbit_sp3 » in ANNEXE/ORBITE which contains orbit file in sp3 format - new routines to convert orbit to a ground track (entetesp3.f90, conv_orbsp3_orbgeo.f90, xyzflh.f90, angle.f90, egalite.f90, common_cons.f90) - 4 routines modified to consider the new feature with sp3 files (modele.f90, hf_jason_doris_freq.f90, calcul_dfsat.f90 and interpol_datemes.f90) The technical note has been updated to consider this evolution. To use the new feature you can read the part 3 of the technical note. Before the orbit change (May 3th 2012), the file "jason_cycle_dates" was been updated regularly by the Central Bureau. Now, it is not any more necessary to update it, the final version of this file is contained in this directory. Recall us, this input file is necessary when we use the Topex mean ground track (the program needs an input file "jason_cycle_dates" which contains,for each Jason cycle, the cycle number and the begin date of the cycle in CNES Julian day, more details below). A regular update of the model is also done by considering the news DORIS data since the last update. By using data between February 20th 2009 and January 6th 2012, we determine the recent evolution of the model parameters. The amplitude parameter has changed and the model has been modified in consequently (only the routine hf_jason_dorisfreq.f90). For those who had already installed a previous version, we recommend to proceed to the complete installation of the new version. Reference: 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 Issue, P. Willis (Ed.), JOURNAL OF GEODESY 80(8-11):507-523, DOI: 10.1007/s00190-006-0068-2 Contacts: Jean-Michel.Lemoine@cnes.fr hCapdeville@cls.fr ids.central.bureau@cls.fr Relationship between CNES Julian Day and modified Julian Day (MJD) MJD= CNES Julian Day + 33282.0 Relationship between MJD and day of year (DOY): ---------------------------------------------- Year MJD Year MJD ---------------------------------------------- 1991 48256 + DOY 2006 53735 + DOY 1992 48621 + DOY 2007 54100 + DOY 1993 48987 + DOY 2008 54465 + DOY 1994 49352 + DOY 2009 54831 + DOY 1995 49717 + DOY 2010 55196 + DOY 1996 50082 + DOY 2011 55561 + DOY 1997 50448 + DOY 2012 55926 + DOY 1998 50813 + DOY 2013 56292 + DOY 1999 51178 + DOY 2014 56657 + DOY 2000 51543 + DOY 2015 57022 + DOY 2001 51908 + DOY 2016 57387 + DOY 2002 52274 + DOY 2017 57753 + DOY 2003 52639 + DOY 2018 58118 + DOY 2004 53004 + DOY 2019 58483 + DOY 2005 53370 + DOY 2020 58848 + DOY