Abstract's details
EIGEN-GRGS.RL03.MEAN-FIELD: new mean gravity field model for altimetric satellite orbit computation
Event: 2014 IDS Workshop
Session: Precise orbit modeling and Precise Orbit Determination
Presentation type: Oral
We present a new mean gravity field model for the computation of altimetric satellites orbits, EIGEN-GRGS.RL03.MEAN-FIELD.
The time-variable part of this mean field extends to degree and order 80, based on the recent reiteration of the computation of the GRACE time series of solutions performed at CNES/GRGS, named "Release 03".
EIGEN-GRGS.RL03.MEAN-FIELD is complete to degree and order 260.
It is based on EIGEN-6S2 for the part between degree 81 and 260.
The time-variable gravity (TVG) coefficients between degrees 1 and 80 are obtained from a regression on the GRGS-RL03-v1 monthly time series (2003-2012). For degree 2 this TVG part is extended to 1985-2012 through the use of a GRGS SLR-only (Lageos+Lageos-2) solution between 1985 and 2003.
Outside of the measurements period (1985-2012 for degree 2, 2003-2012 for degrees 3 to 80), the gravity field is extrapolated with a zero-slope assumption.
The modeling of the TVG part includes, as was the case for EIGEN-6S2:
Two annual and two semi-annual coefficients
One bias and one drift for each year.
The bias and drift are in general coherent so that the result is a piece wise linear function, except in the case of earthquakes. Three major earthquakes have been introduced in the modelling: Sumatra on 2004/12/26, Concepcion on 2010/02/27 and Sendai on 2011/03/11.
We will present the standards used for the computation, the characteristics of this new mean field and some evaluations in terms of orbit accuracy performance.
Back to the list of abstractThe time-variable part of this mean field extends to degree and order 80, based on the recent reiteration of the computation of the GRACE time series of solutions performed at CNES/GRGS, named "Release 03".
EIGEN-GRGS.RL03.MEAN-FIELD is complete to degree and order 260.
It is based on EIGEN-6S2 for the part between degree 81 and 260.
The time-variable gravity (TVG) coefficients between degrees 1 and 80 are obtained from a regression on the GRGS-RL03-v1 monthly time series (2003-2012). For degree 2 this TVG part is extended to 1985-2012 through the use of a GRGS SLR-only (Lageos+Lageos-2) solution between 1985 and 2003.
Outside of the measurements period (1985-2012 for degree 2, 2003-2012 for degrees 3 to 80), the gravity field is extrapolated with a zero-slope assumption.
The modeling of the TVG part includes, as was the case for EIGEN-6S2:
Two annual and two semi-annual coefficients
One bias and one drift for each year.
The bias and drift are in general coherent so that the result is a piece wise linear function, except in the case of earthquakes. Three major earthquakes have been introduced in the modelling: Sumatra on 2004/12/26, Concepcion on 2010/02/27 and Sendai on 2011/03/11.
We will present the standards used for the computation, the characteristics of this new mean field and some evaluations in terms of orbit accuracy performance.