Guilhem Moreaux

TL;DR: Evaluation of the intrinsic quality of the new DORIS Terrestrial Reference Frame shows that the addition of data from the new missions equipped with the latest generation of DORis receiver results in an internal position consistency of 10 mm or better after mid-2008.

Abstract: The Least-squares collocation (LSC) method is commonly used in geodesy, but generally associated with globally supported covariance functions, i.e. with dense covariance matrices. We consider locally supported radial covariance functions, which yield sparse covariance matrices. Having many zero entries in the covariance matrice can both greatly reduce computer storage requirements and the number of floating point operations needed in computation. This paper reviews some of the most well-known compactly supported radial covariance functions (CSRCFs) that can be easily substituted to the usually used covariance functions. Numerical experiments reveals that these finite covariance functions can give good approximations of the Gaussian, second- and third-order Markov models. Then, interpolation of KMS02 free-air gravity anomalies in Azores Islands shows that dense covariance matrices associated with Gaussian model can be replaced by sparse matrices from CSRCFs resulting in memory savings of one-fortieth and with 90% of the solution error less than 0.5 mGal.

TL;DR: Improvements seen when using different reference frames, such as the original ITRF2008 solution, are demonstrated for precise orbit determination of altimeter satellites TOPEX/Poseidon and Jason-2 over selected periods spanning 1993–2013.

TL;DR: The International DORIS Service (IDS) was created in 2003 under the umbrella of the International Association of Geodesy (IAG) to foster scientific research related to the French DG-DORIS tracking system and to deliver scientific products as mentioned in this paper.

TL;DR: Improvement work aimed at improving the DORIS Starec ground antenna phase center definition model is described, which results in a reduction in the scatter to ±1 mm and the phase center position has been kept unchanged and associated phase law has been updated.