Systematic biases in DORIS-derived geocenter time series related to solar radiation pressure mis-modeling

Multi-technique comparison of troposphere zenith delays and gradients during CONT08

“…Zenith troposphere parameters were estimated at the start of passes, and only if the previous reset was not within 20 minutes (see Bock et al, 2010, for a more detailed discussion). This solution is as close as possible to the IERS Conventions 2003 (McCarthy andPetit, 2004), and it also includes the most recent improvement in DORIS data analysis, in particular in terms of solar radiation pressure modelling (Gobinddass et al, 2009a(Gobinddass et al, , 2009b as well as in terms of atmospheric drag parameterization (Gobinddass et al, 2010).…”

Improving DORIS geocenter time series using an empirical rescaling of solar radiation pressure models

“…If the estimated daily coefficients are sufficiently stable with time, they can be approximated as a constant that will be later used for recomputing all DORIS data (current and future). However, we must first check the complete time series to look for possible discontinuities (see special case of TOPEX/Poseidon on July 27th 1993, in Gobinddass et al, 2009), or other problems (periodic signals, change in slope, etc. ).…”

“…A recent study (Gobinddass et al, 2009) demonstrated that a large part of these observed systematic errors at 118 days and at 1 year periods (draconitic/draconic 1 period of TOPEX/Poseidon and SPOTs satellites) can be removed by modifying the DORIS data analysis strategy, by rescaling the solar radiation pressure (SRP) models with a constant empirical term. As this study only used old data from TOPEX/Poseidon and SPOT-2 DORIS data, the goal of this article is to extend this study to all DORIS satellites in orbit since 1993 and to check for any improvement in the DORIS geocenter estimation.…”

“…Gobinddass et al (2009) found that part of the systematic errors at 118 days and 1 year can be significantly reduced by rescaling the current solar radiation pressure models using satellite-dependent empirical models. Here we extend this study to all DORIS satellites and propose a complete set of empirical solar radiation parameter coefficients.…”

Collinearity assessment of geocentre coordinates derived from multi-satellite SLR data

“…The final publication is available at Springer via http://dx.doi.org/10.1007/s00190-015-0845-x the modelling of solar radiation pressure (SRP) effects. Mismodelling of SRP introduces spurious signals in the time series of geocentre coordinates estimated from GNSS (Meindl et al 2013) and DORIS data (Gobinddass et al 2009a), particularly along the Z axis. GNSS geocentre motion estimates are particularly vulnerable to modelling errors due to their strong collinearity with other parameters routinely estimated in standard GNSS data analyses, as demonstrated by Rebischung et al (2014).…”