SkyMapper DR4 Image Access By downloading SkyMapper data you agree to observe the policies published at http://skymapper.anu.edu.au/policies/ Image name MIME-type of the requested image SkyMapper filter (u,v,g,r,i,z) Image download URL Download PNG preview Download FITS Download FITS bitmask ICRS Right Ascension of the image centre ICRS Declination of the image centre On-sky exposure time Modified Julian Date of exposure start Angular size of image Image size in pixels WCS pixel scale of each image axis Unique image identifier [image_id]-[ccd] Type of image Instrument name Number of image axes Coordinate system reference frame Tangent plane projection with a polynomial distortion function described by coefficients provided in a set of PVi_j keywords. The first image axis represents Right Ascension and the second represents Declination