Showing papers by "Mariateresa Crosta published in 2010"
INAF1
TL;DR: In this article, the authors set the level of reciprocal consistency of two relativistic models, GREM and RAMOD (Gaia, ESA mission), in order to guarantee a physically correct definition of the light's local direction to a star.
Abstract: The high accuracy achievable by modern space astrometry requires the use of General Relativity to model the stellar light propagation through the gravitational field encountered from a source to a given observer inside the Solar System. The general relativistic definition of an astrometric measurement needs an appropriate use of the concept of reference frame, which should then be linked to the conventions of the IAU resolutions. On the other hand, a definition of the astrometric observables in the context of General Relativity is also essential for finding the stellar coordinates and proper motion uniquely, this being the main physical task of the inverse ray-tracing problem. The aim of this work is to set the level of reciprocal consistency of two relativistic models, GREM and RAMOD (Gaia, ESA mission), in order to guarantee a physically correct definition of the light's local direction to a star and deduce the star coordinates and proper motions at the level of accuracy required by these models consistently with the IAU's adopted reference systems.
23 citations
TL;DR: In this article, the authors show how the geometrical framework of models like RAMOD, initially developed for astrometric observations, constitutes an appropriate physical environment for back tracing a light ray conforming to the intrinsic accuracy of space-time.
Abstract: Advancement in astronomical observations and technical instrumentation requires coding light propagation at high level of precision; this could open a new detection window of many subtle relativistic effects suffered by light while it is propagating and entangled in the physical measurements. Light propagation and its subsequent detection should indeed be conceived in a fully relativistic context, in order to interpret the results of the observations in accordance with the geometrical environment affecting light propagation itself, as an unicum surrounding universe. One of the most intriguing aspects is the boost towards the development of highly accurate models able to recon- struct the light path consistently with General Relativity and the precepts of measurements. This paper deals with the complexity of such a topic by showing how the geometrical framework of models like RAMOD, initially developed for astrometric observations, constitutes an appropriate physical environment for back tracing a light ray conforming to the intrinsic accuracy of space-time. This article discusses the reasons why RAMOD stands out among the existent approaches applied to the light propagation problem and provides a proof of its capability in recasting recent literature cases.
19 citations
INAF1
TL;DR: The Italian Data Processing Center Turin (DPCT) as discussed by the authors is hosting and operated at ALTEC in Turin to provide infrastructure and operations support to the Astrometric Verification Unit (AVU) activities for CU3.
Abstract: Gaia is an ESA Cornerstone mission, scheduled to be launched in spring 2013, dedicated to precisely measure the positions and motions of over a billion stars in our galaxy: the Milky Way. Gaia Data Processing Center Turin (DPCT), the Italian DPC, is hosted and operated at ALTEC in Turin. The primary objective of DPCT is to provide the infrastructure and operations support to the Astrometric Verification Unit (AVU) activities for CU3 and the Italian participation to the Gaia data processing tasks. DPCT will archive all of the data, produced for and delivered to DPAC as part of the Italian contribution to the activities of CU4, CU5, CU7, and CU8.
2 citations