--- header unit 0: primary ---
SIMPLE = T / file does conform to FITS standard
BITPIX = 16 / number of bits per data pixel
NAXIS = 0 / number of data axes
EXTEND = T / FITS dataset may contain extensions
COMMENT FITS (Flexible Image Transport System) format is defined in 'Astronomy
COMMENT and Astrophysics', volume 376, page 359; bibcode: 2001A&A...376..359H
DATE = '2014-06-02T20:36:02' / file creation date (YYYY-MM-DDThh:mm:ss UT)
--- header unit 1: binary table ---
XTENSION = 'BINTABLE' / binary table extension
BITPIX = 8 / 8-bit bytes
NAXIS = 2 / 2-dimensional binary table
NAXIS1 = 4 / width of table in bytes
NAXIS2 = 3145728 / number of rows in table
PCOUNT = 0 / size of special data area
GCOUNT = 1 / one data group (required keyword)
TFIELDS = 1 / number of fields in each row
TTYPE1 = 'SIGNAL' / label for field 1
TFORM1 = '1E' / data format of field: 4-byte REAL
TUNIT1 = '' / physical unit of field
EXTNAME = 'BINTABLE' / name of this binary table extension
PIXTYPE = 'HEALPIX' / HEALPIX Pixelisation
ORDERING = 'RING' / Pixel ordering scheme, either RING or NESTED
NSIDE = 512 / Resolution parameter for HEALPIX
COORDSYS = 'G' / Pixelisation coordinate system
COMMENT G = Galactic, E = ecliptic, C = celestial = equatorial