WMAP Reduced Resolution Single Year Q,U Maps Per Differencing Assembly
FITS Header Information

The maps are contained in a binary table Q_POLARISATION and U_POLARISATION columns. A second table supplies the noise covariance matrices of the polarization maps.

Primary Header

SIMPLE  =                    T /FITS format
BITPIX  =                    8 /Dummy primary header
NAXIS   =                    0 /No data is associated with this header
EXTEND  =                    T /Extensions may (will!) be present
RESOLUTN=                    4 /Resolution Index
PIXTYPE = 'HEALPIX '           /Pixel algorigthm
ORDERING= 'NESTED  '           /Ordering scheme
NSIDE   =                   16 /Resolution Parameter
NPIX    =                 3072 /Number of pixels
FIRSTPIX=                    0 /First pixel (0 based)
LASTPIX =                 3071 /Last pixel (0 based)
COMMENT This file contains WMAP Polarization (Q and U)
COMMENT Res 4 skymaps for the frequency band indicated by
COMMENT the FREQ keyword.
COMMENT Seven years of data went into the map
DATE    = '2009-12-31T21:37:49' /file creation date (YYYY-MM-DDThh:mm:ss UT)
TELESCOP= 'WMAP    '           /Wilkinson Microwave Anisotropy Probe
REFERENC= 'WMAP Explanatory Supplement:  http://lambda.gsfc.nasa.gov/' /
STOKES  = 'QU      '           /
RELEASE = 'DR4     '           /WMAP Release
FREQ    = ' band   '           /Frequency band
END

Polarization Map Table

XTENSION= 'BINTABLE'           /binary table extension
BITPIX  =                    8 /8-bit bytes
NAXIS   =                    2 /2-dimensional binary table
NAXIS1  =                    8 /width of table in bytes
NAXIS2  =                 3072 /number of rows in table
PCOUNT  =                    0 /size of special data area
GCOUNT  =                    1 /one data group (required keyword)
TFIELDS =                    2 /number of fields in each row
TTYPE1  = 'Q_POLARISATION '    /
TFORM1  = 'E       '           /
TUNIT1  = 'mK,thermodynamic'   /
TTYPE2  = 'U_POLARISATION '    /
TFORM2  = 'E       '           /
TUNIT2  = 'mK,thermodynamic'   /
EXTNAME = 'Stokes Maps'        /
DATE    =                    0 /
PIXTYPE = 'HEALPIX '           /
ORDERING= 'NESTED  '           /
NSIDE   =                   16 /
FIRSTPIX=                    0 /
LASTPIX =                 3071 /
END

More information concerning the contents of this file is available.