Category: Operational news

To improve the long-term stability of the GDR orbit solutions, new orbit determination standards are applied for Envisat which are now included in the Ssalto/Duacs products.

Precise Orbit Determination models applied in GDR orbits since July 2008 were referred as produced with GDR-C standards. New orbit standards, named GDR-D, are now applied for Envisat to improve the long-term stability of the GDR orbit solutions from:

• January 21^st 2012, for the first MOE in IGDR,
• cycle 111, for the first POE in GDR.

Ssalto/Duacs products currently integrate those new orbit standards in real-time and near-real time products. The main expected impact of this improvement should be a jump in data induced by the POE standards changes in GDR; which should be taken into account in the climate studies. NB: These new standards GDR-D only concern the orbit standards; they are not applied to the product standard reference which are currently referred as GDR-C (See the tables on Corrections and models applied for NRT and RT products, in the <link fileadmin documents data tools hdbk_duacs.pdf download>Ssalto/Duacs User Handbook). Feel free to contact us if you have any questions.

Further information:

• <link internal-link>Precise Orbit Determination
• L.Cerri et al.: Improving the long-term stability of the GDR orbit solutions, OSTST 2011 presentation (<link http: www.aviso.oceanobs.com fileadmin documents ostst oral>pdf).