Towards a robust estimation of orientation parameters between ICRF and $Gaia$ celestial reference frames

Abstract

An analysis of the source position differences between VLBI-based ICRF and $Gaia$-CRF catalogues is a key step in assessing their systematic errors and determining their mutual orientation. One of the main factors that limits the accuracy of determination of the orientation parameters between two frames is the impact of outliers. To mitigate this effect, a new method is proposed based on pixelization data over the equal-area cells, followed by median filtering of the data in each cell. After this, a new data set is formed, consisting of data points near-uniformly distributed over the sphere. The vector spherical harmonics (VSH) decomposition is then applied to this data to finally compute the orientation parameters between ICRF and $Gaia$ frames. To validate the proposed approach, a comparison was made of the ICRF3-SX and $Gaia$~DR2 catalogues using several methods for outliers removal. The results of this work showed that the proposed method is practically insensitive to outliers and thus provides much more robust results of catalogues comparison than the methods used so far. This conclusion was confirmed by analogous test comparison of the $Gaia$~DR2 and OCARS catalogues.

arXiv commentAccepted in MNRAS

References in corpus (18)

• HEALPix -- a Framework for High Resolution Discretization, and Fast Analysis of Data Distributed on the Sphere
• Gaia Data Release 2: The astrometric solution
• Gaia Early Data Release 3: The astrometric solution
• The third realization of the International Celestial Reference Frame by very long baseline interferometry
• Gaia Data Release 2: The Celestial reference frame (Gaia-CRF2)
• Analysis of astrometric catalogues with vector spherical harmonics
• Gaia Early Data Release 3: Acceleration of the solar system from Gaia astrometry
• Gaia Data Release 1: The reference frame and the optical properties of ICRF sources
• On the VLBI measurement of the Solar System acceleration
• The local stellar velocity field via vector spherical harmonics
• A new version of the OCARS catalog of Optical Characteristics of Astrometric Radio Sources
• The precious set of radio-optical reference frame objects in the light of Gaia DR2 data
• A new equal-area isolatitudinal grid on a spherical surface
• The current best estimate of the Galactocentric distance of the Sun based on comparison of different statistical techniques
• Systematics and accuracy of VLBI astrometry: What can be learned from a comparison with Gaia Data Release 2
• Towards the ICRF3: astrometric comparison of the USNO 2016A VLBI solution with ICRF2 and Gaia DR1
• Realization of a multifrequency celestial reference frame through a combination of normal equation systems
• On the selection of prospective sources for ICRF extension

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