Scanning Beams

The polarized scanning beams are released as maps of the Stokes polarization parameters of the electromagnetic field. Main Beam, Intermediate Beam, and Sidelobes are released separately.

Note on the file format

The stokes map files consist in four columns containing the stokes parameters for each sample, encoding all the information on the field intensity and polarization properties. The columns are called "Beamdata" , "BeamdataQ", "BeamdataU" and "BeamdataV", containing respectively the [math]I[/math], [math]Q[/math], [math]U[/math] and [math]V[/math] Stokes parameters. There are differences in the data format between the Main Beam and the near and far Sidelobes.

Main Beams are sampled with a grid map on the tangent space. The dimension of the grid is given by the keywords "Nx" and "Ny", representing the number of columns and rows of the grid map. The four stokes columns contain the succession of the [math]Nx \times Ny[/math] samples of the map. The keywords "Xcentre" and "Ycentre" contain the coordinates of the beam maximum.

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 succession of Nphi Stokes parameters for each [math]\theta[/math].