This survey is a mosaic of images taken by the ROSAT Wide Field Camera and comprises of 12,743 seperates fields in each of two filters. Each field covers a region 2.6°; x 2.6°; with a 0.3°; overlap. Currently, this data is not a complete coverage of the sky; regions near the northern ecliptic pole are currently not included. Provenance: University of Leicester. This is a service of NASA HEASARC.