Differences between USNO-B and PPMXL in positions and proper motions, on an all-sky one-degree grid. At each gridpoint we give the differences X(PPMXL)- X(USNO-B1.0) averaged over all stars in a sqrt(2)/2-degrees environment around the gridpoint given. The corrections given here should bring USNO-B based astrometry to the ICRS.
This data center is not currently reporting usage information. For information on how your repository can submit usage information, please see our documentation.
We found no citations for this service. For information on how to provide citation information, please see our documentation.