We use methods of differential astrometry to construct a small field inertial
reference frame stable at the micro-arcsecond level. Such a high level of
astrometric precision can be expected with the end-of-mission standard errors
to be achieved with the Gaia space satellite using global astrometry. We
harness Gaia measurements of field angles and look at the influence of the
number of reference stars and the star's magnitude as well as astrometric
systematics on the total error budget with the help of Gaia-like simulations
around the Ecliptic Pole in a differential astrometric scenario. We find that
the systematic errors are modeled and reliably estimated to the $\mu$as level
even in fields with a modest number of 37 stars with G $<$13 mag over a 0.24
sq.degs. field of view for short time scales of the order of a day with
high-cadence observations such as those around the North Ecliptic Pole during
the EPSL scanning mode of Gaia for a perfect instrument. The inclusion of the
geometric instrument model over such short time scales accounting for
large-scale calibrations requires fainter stars down to G = 14 mag without
diminishing the accuracy of the reference frame. We discuss several future
perspectives of utilizing this methodology over different and longer
timescales.
Description
The Short Term Stability of a Simulated Differential Astrometric
Reference Frame in the Gaia era
%0 Generic
%1 abbas2017short
%A Abbas, U.
%A Bucciarelli, B.
%A Lattanzi, M. G.
%A Crosta, M.
%A Gai, M.
%A Smart, R.
%A Sozzetti, A.
%A Vecchiato, A.
%D 2017
%K astrometry
%T The Short Term Stability of a Simulated Differential Astrometric
Reference Frame in the Gaia era
%U http://arxiv.org/abs/1702.04989
%X We use methods of differential astrometry to construct a small field inertial
reference frame stable at the micro-arcsecond level. Such a high level of
astrometric precision can be expected with the end-of-mission standard errors
to be achieved with the Gaia space satellite using global astrometry. We
harness Gaia measurements of field angles and look at the influence of the
number of reference stars and the star's magnitude as well as astrometric
systematics on the total error budget with the help of Gaia-like simulations
around the Ecliptic Pole in a differential astrometric scenario. We find that
the systematic errors are modeled and reliably estimated to the $\mu$as level
even in fields with a modest number of 37 stars with G $<$13 mag over a 0.24
sq.degs. field of view for short time scales of the order of a day with
high-cadence observations such as those around the North Ecliptic Pole during
the EPSL scanning mode of Gaia for a perfect instrument. The inclusion of the
geometric instrument model over such short time scales accounting for
large-scale calibrations requires fainter stars down to G = 14 mag without
diminishing the accuracy of the reference frame. We discuss several future
perspectives of utilizing this methodology over different and longer
timescales.
@misc{abbas2017short,
abstract = {We use methods of differential astrometry to construct a small field inertial
reference frame stable at the micro-arcsecond level. Such a high level of
astrometric precision can be expected with the end-of-mission standard errors
to be achieved with the Gaia space satellite using global astrometry. We
harness Gaia measurements of field angles and look at the influence of the
number of reference stars and the star's magnitude as well as astrometric
systematics on the total error budget with the help of Gaia-like simulations
around the Ecliptic Pole in a differential astrometric scenario. We find that
the systematic errors are modeled and reliably estimated to the $\mu$as level
even in fields with a modest number of 37 stars with G $<$13 mag over a 0.24
sq.degs. field of view for short time scales of the order of a day with
high-cadence observations such as those around the North Ecliptic Pole during
the EPSL scanning mode of Gaia for a perfect instrument. The inclusion of the
geometric instrument model over such short time scales accounting for
large-scale calibrations requires fainter stars down to G = 14 mag without
diminishing the accuracy of the reference frame. We discuss several future
perspectives of utilizing this methodology over different and longer
timescales.},
added-at = {2017-02-17T23:05:49.000+0100},
author = {Abbas, U. and Bucciarelli, B. and Lattanzi, M. G. and Crosta, M. and Gai, M. and Smart, R. and Sozzetti, A. and Vecchiato, A.},
biburl = {https://www.bibsonomy.org/bibtex/2d1e2ad875538b0747a6c5facaa5ec718/superjenwinters},
description = {The Short Term Stability of a Simulated Differential Astrometric
Reference Frame in the Gaia era},
interhash = {6a355e7a21106918e5a0f8034883608a},
intrahash = {d1e2ad875538b0747a6c5facaa5ec718},
keywords = {astrometry},
note = {cite arxiv:1702.04989Comment: 14 pages, 7 figures, accepted by Publications of the Astronomical Society of the Pacific},
timestamp = {2017-02-17T23:05:49.000+0100},
title = {The Short Term Stability of a Simulated Differential Astrometric
Reference Frame in the Gaia era},
url = {http://arxiv.org/abs/1702.04989},
year = 2017
}