Scanning Beams

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.

File Names

The file names are of the form:

LFI_ScanBeam-{mb,ib,sl}_{fff}-{rrr}_R2.{nn}.stokes

where

• 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.

File format

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 [math]I[/math], [math]Q[/math], [math]U[/math] and [math]V[/math]. There are differences in the data format between the Main Beam and the near and far Sidelobes.

Main Beams are projected on the tangent plane to the sphere, and sampled on a grid. The dimension of the grid is given by the keywords "Nx" and "Ny", representing the number of columns and rows. Each of the four columns contain the sequence of the [math]Nx \times Ny[/math] samples of the map in row major order. The keywords "Xcentre" and "Ycentre" contain the coordinates of the beam maximum (i.e. where the sphere intersect the tangent plane).

Sidelobes are sampled on the sphere. The resolution in [math]\theta[/math] and [math]\phi[/math] is given by the keywords "Ntheta" and "Nphi". The columns contain the sequence of Nphi Stokes parameters for each [math]\theta[/math].