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Spatial correlations in the Gaia astrometric solution

Holl, Berry LU ; Hobbs, David LU and Lindegren, Lennart LU (2010) 261st Symposium of the International-Astronomical-Union In Relativity in Fundamental Astronomy: Dynamics, Reference Frames, and Data Analysis (IAU Symposium) 261. p.320-324
Abstract
Accurate characterization of the astrometric errors in the forthcoming Gaia catalogue is essential for making optimal use of the data. Using small-scale numerical simulations of the astrometric solution, we investigate the expected spatial correlation between the astrometric errors of stars as function of their angular separation. Extrapolating to the full-scale solution for the final Gala catalogue, we find that the expected correlations are generally very small, but could reach some fraction of a percent for angular separations smaller than about one degree. The spatial correlation length is related to the size of the field of view of Gala., while the maximum correlation coefficient is related to the mean number of stars present in the... (More)
Accurate characterization of the astrometric errors in the forthcoming Gaia catalogue is essential for making optimal use of the data. Using small-scale numerical simulations of the astrometric solution, we investigate the expected spatial correlation between the astrometric errors of stars as function of their angular separation. Extrapolating to the full-scale solution for the final Gala catalogue, we find that the expected correlations are generally very small, but could reach some fraction of a percent for angular separations smaller than about one degree. The spatial correlation length is related to the size of the field of view of Gala., while the maximum correlation coefficient is related to the mean number of stars present in the field at any time. Our scalable simulation tool (AGISLab) makes it possible to characterize the astrometric errors and correlations, e.g., as functions of position and magnitude. (Less)
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author
organization
publishing date
type
Chapter in Book/Report/Conference proceeding
publication status
published
subject
keywords
space vehicles, methods: statistical, methods: data analysis, catalogs, Astrometry, reference systems
in
Relativity in Fundamental Astronomy: Dynamics, Reference Frames, and Data Analysis (IAU Symposium)
volume
261
pages
320 - 324
publisher
Cambridge University Press
conference name
261st Symposium of the International-Astronomical-Union
external identifiers
  • wos:000280569700051
  • scopus:84864452179
ISSN
1743-9213
1743-9221
DOI
10.1017/S1743921309990573
language
English
LU publication?
yes
id
8900cfa4-cc8b-4552-aea5-7c21bb04a9a6 (old id 1678391)
date added to LUP
2010-09-21 09:37:26
date last changed
2018-01-07 04:41:25
@inproceedings{8900cfa4-cc8b-4552-aea5-7c21bb04a9a6,
  abstract     = {Accurate characterization of the astrometric errors in the forthcoming Gaia catalogue is essential for making optimal use of the data. Using small-scale numerical simulations of the astrometric solution, we investigate the expected spatial correlation between the astrometric errors of stars as function of their angular separation. Extrapolating to the full-scale solution for the final Gala catalogue, we find that the expected correlations are generally very small, but could reach some fraction of a percent for angular separations smaller than about one degree. The spatial correlation length is related to the size of the field of view of Gala., while the maximum correlation coefficient is related to the mean number of stars present in the field at any time. Our scalable simulation tool (AGISLab) makes it possible to characterize the astrometric errors and correlations, e.g., as functions of position and magnitude.},
  author       = {Holl, Berry and Hobbs, David and Lindegren, Lennart},
  booktitle    = {Relativity in Fundamental Astronomy: Dynamics, Reference Frames, and Data Analysis (IAU Symposium)},
  issn         = {1743-9213},
  keyword      = {space vehicles,methods: statistical,methods: data analysis,catalogs,Astrometry,reference systems},
  language     = {eng},
  pages        = {320--324},
  publisher    = {Cambridge University Press},
  title        = {Spatial correlations in the Gaia astrometric solution},
  url          = {http://dx.doi.org/10.1017/S1743921309990573},
  volume       = {261},
  year         = {2010},
}