We released maps of the Stokes parameters of the band-averaged scanning beams. The Stokes parameters maps contain the complete information about the field intensity and polarization properties. Main Beam, Intermediate Beam, and Sidelobes are released separately.
The file names are of the form:
- fff denotes the frequency
- mb denotes the Main Beams
- ib denotes the Intermediate Beam
- sl denotes the Sidelobes
- rrr denotes the radiometer
- R2.nn is the version.
At the present time, HFI is not releasing the Scanning Beams.
FITS file structure
The FITS files contain a primary extension with no data and a minimal header, and one BINTABLE extension with data and with a description of the data in the header keywords. The BINTABLE extension consist in four columns, each containing the array of one Stokes parameter. The columns are called:
- Beamdata , containing
- BeamdataQ, containing
- BeamdataU, containing
- BeamdataV, containing .
Main Beam, Intermediate Beams and Sidelobes are saved with a different data format:
- Main Beams are projected on the tangent plane to the sphere, and sampled on a grid. The grid include an angular region gexpressed by the keyword angularCut, and its dimensions are given by the keywords Nx and Ny, representing the number of columns and rows.
Each column of the BINDATA extension contain the sequence of thesamples of the map in row major order. The keywords Xcentre and Ycentre express the coordinates of the beam maximum (i.e. where the sphere intersect the tangent plane).
|Column Name||Data Type||Units||Description|
|BEAMDATA||Real*4||none||Stokes parameter I|
|BEAMDATAQ||Real*4||none||Stokes parameter Q|
|BEAMDATAU||Real*4||none||Stokes parameter U|
|BEAMDATAV||Real*4||none||Stokes parameter V|
|Nx||Int||601||X axis samples number||X axis aligned with the direction of the S arm|
|Ny||Int||601||Y axis samples number||Y axis aligned with the direction of the M arm|
|Xcentre||Int||301||X coordinate of the beam centre|
|Ycentre||Int||301||Y coordinate of the beam centre|
|Xdelta||Real*4||X step in radians|
|Ydelta||Real*4||Y step in radians|
- Intermediate Beams and Sidelobes are sampled on the sphere. The resolution in and is given by the keywords "Ntheta" and "Nphi". The columns contain the sequence of Nphi Stokes parameters for each .
The stokes map files consist in four columns containing the Stokes parameters for each sample. The columns are called "Beamdata" , "BeamdataQ", "BeamdataU" and "BeamdataV", containing respectively, , and . There are differences in the data format between the Main Beam and the near and far Sidelobes.
(Planck) Low Frequency Instrument
(Planck) High Frequency Instrument
Flexible Image Transfer Specification