Abstract
The individual uncertainties of the proper motion catalogues SPM_{MC}, XPM and UCAC4 are determined using the method of Wielen, in an area of the sky containing the Magellanic Clouds. These uncertainties are a measure of the quality and the reliability of these catalogs for kinematical studies. The data preparation begins by cross identifying stars common to the catalogs, and on this sample, systematic differences are detected, modeled and corrected. After applying the Wielen method and evaluating the results, it follows that the catalog of best astrometric quality is UCAC4, with an uncertainty of (epsilon _{mu _{alpha } cos(delta )},epsilon _{mu _{delta }})=(2.92,1.90) mas/yr. The SPM_{MC} has a quality similar to the previous catalogue, expressed as (epsilon _{mu _{alpha } cos(delta )},epsilon _{mu _{delta }})_{frac {SPM_{MC}}{UCAC4}}=(1.11,1.53) times the UCAC4. Finally the quality for the XPM differs significantly from the other two catalogues, its errors are (epsilon _{mu _{alpha } cos(delta )},epsilon _{mu _{delta }})_{(XPM)/(UCAC4)}=(6.32,8.87) times the UCAC4.
