WIPE Regularization

WIPE is a regularized deterministic Fourier synthesis method. We know from inverse problems theory that extrapolation is forbidden, and interpolation allowed to a certain extent. The first step is to define the amount of interpolation that we want to perform in the Fourier space from the gridded experimental data information.

The aperture to synthesize is defined as the ellipse fitting in the best manner the experimental data. According to the confidence we put in data, one can expand this ellipse using two multiplicative factors (variable APERTURE) applied on the major and minor axis. At the end of this step a window will appear with three areas showing the gridded experimental aperture, the synthesized aperture and the superposition of the two first ones (cf. figure 1).

  

Figure 1: of aperture window.

Once the aperture to synthesize is defined, one can then compute the synthetic beam or ``Neat Beam'', using the power method to construct the corresponding spheroidal filter. The ``Dusty Beam'' is the one related to the experimental aperture. We also compute the ``Dusty Map'', as opposed to the clean ``Dirty Map'', because it is apodized by the Neat Beam. The window displaying these three images is displayed as the BEAM window (cf. figure 2).

  

Figure 2: of a BEAM window.