NOTES:
    1.  These statistics are computed from the master WCS solutions for
	the CCDs in the Mosaic.  These solutions map pixels to celestial
	coordinates and include the optical and sky projection effects.
    2.  The field rotation is a clockwise angle of the declination axis from
	the image column axis.  For example an angle of 270 means that
	declination increases to the left in an unflipped display.
    3.  The CCD rotation is a relative rotation from the mean field
	rotation.
    4.  The gaps are computed from the distance on the sky of the indicated
	pixels as shown in the arcsec column.  The pixel gap is computed
	from the arc second distance using the mean pixel scale.  The
	millimeter gap is derived from the pixel gap using the average
	pixel size.  Because this is derived from the sky the gap is not
	precisely the true physical gap.
    5.  The offsets are derived from the sky distance between the
	center of each CCD and the indicated reference point.  The
	sky distance is converted to pixels using the mean pixel scale.