Single detector maps

Introduction

There are no single detector maps in the first release. This section will serve for later releases.

Maps for single detectors are built for full or part of the mission and are used primarily for characterization purposes: while the ones built with an unpolarized detector have a scientific value, the ones built using a polarization sensitive one have little, since, among other things, the polarization angle varies around the sky. Each signal map will be accompanied by a hit map and a variance map. All maps are in Healpix format, with Nside of 2048 for HFI and of 1024 for LFI, in Galactic coordinates, and Nested ordering. The three maps will be packaged into a FITS files with a single BINTABLE extension containing a table of three columns; the structure of the FITS file is given in the FITS file structure section below.

The FITS filenames are of the form {H|L}FI_{detname}_nnnn_yyyymmdd_{type}_{mission}.fits, where detname is a detector identifier, and nnnn is the Healpix Nside of the map, the optional type indicates the subset of input data used, and mission indicates the coverage period, i.e., full, nominal, or survey_n (TBC; an alternative of the type {H|L}FI_detname_{type}_{mission}_Rn.mm.fits is being considered, where Rn.mm is the release number). A full list of products, by their names, is given in the List of products below. These

HFI Processing

See Frequency Maps section

LFI PRocessing

TBW

List of products

First release

None

Second Release

TBW

FITS file structure

The FITS file structure is like that of Intensity-only frequency maps as described in the next section

Header keywords

A typical header for the extension is

XTENSION= 'BINTABLE'           / binary table extension                         
BITPIX  =                    8 / 8-bit bytes                                    
NAXIS   =                    2 / 2-dimensional binary table                     
NAXIS1  =                   12 / width of table in bytes                        
NAXIS2  =             50331648 / number of rows in table                        
PCOUNT  =                    0 / size of special data area                      
GCOUNT  =                    1 / one data group (required keyword)              
TFIELDS =                    3 / number of fields in each row                   
TTYPE1  = 'I_Stokes'           / label for field   1                            
TFORM1  = '1E8     '           / data format of field: 4-byte REAL              
TUNIT1  = 'K_CMB   '           / physical unit of field                         
TTYPE2  = 'Hits    '           / label for field   2                            
TFORM2  = '1J      '           / data format of field: 4-byte INTEGER           
TUNIT2  = 'none    '           / physical unit of field                         
TTYPE3  = 'II_cov  '           / label for field   3                            
TFORM3  = '1E8     '           / data format of field: 4-byte REAL              
TUNIT3  = '(K_CMB)^2'          / physical unit of field                         
EXTNAME = 'CH-MAP  '           / name of this binary table extension            
FREQ    = '857     '                                                            
PIXTYPE = 'HEALPIX '                                                            
COORDSYS= 'GALACTIC'                                                            
ORDERING= 'NESTED  '                                                            
FILENAME= 'HFI_857-2_2048_20120210_nominal.fits'                                
NSIDE   =                 2048                                                  
CHANNEL = '857-2   '                                                            
FIRSTPIX=                    0                                                  
LASTPIX =             50331647                                                  
EXTVER  = '1       '                                                            
PROCVER = 'v50     '                                                            
BAD_DATA= '-1.63750E+30'                                                        
COMMENT = 'Rel DR4 '                                                            
END