A METHOD FOR LOCAL RECTIFICATION OF 2MASS POSITIONS WITH UCAC4

作者：Bustos Fierro I H; Calderon J H^*

来源：Revista Mexicana de Astronomia y Astrofisica, 2016, 52(1): 143-153.

• astrometry
• catalogs
• methods: data analysis
• methods: miscellaneous

We propose to locally rectify 2MASS with respect to UCAC4 in order to diminish the systematic differences between these catalogs. We develop a rectification method that starts computing the weighted mean differences 2MASS UCAC4 on a regular grid on the sky. The corrections that are later applied to 2MASS positions are obtained by a spline interpolation of the mean values calculated on the grid. The method is tested in four 3 degrees x 3 degrees fields in the ecliptical zone; after rectification in all of them the systematic differences are reduced well below the random differences. The 2MASS catalog rectified with the proposed method can be regarded as an extension of UCAC4 for astrometry, with an accuracy of around 90 mas in the positions, and with negligible systematic errors, for instance for the astrometric reduction of small field CCD images.

• 出版日期2016-4