Open Access
Table 1
Meaning and dimensions of vectors and matrices used in Sect. 2.1.
| Scalars | |
|---|---|
| n pix | Total number of pixels in image plane |
| & number of cells in uv-grid | |
| nant | Total number of antennas in the array |
| nb | Number of visibilities |
| b | Index for a single visibility. |
Equivalent to  |
|
| τ | Equivalent to  |
| Vectors | |
 |
Residual image vector, size npix |
| ϵ | Vector of ϵ, size npix |
 |
Contains gain products, size nb. see Eq. (12) |
| 1 | Vector containing 1 in every cell, size nb |
 |
Vector of coordinates in differential Fourier |
| plane, of length 3. | |
| ld | Vector of sky coordinates, of length 3. |
| Matrices | |
 |
Visibility seen by a baseline pq at time and |
| frequency t, ν. Size 2 × 2. | |
 |
Fourier kernel for direction d, antenna p and |
one  pair. Size 2 × 2. |
|
| Jp,tν | Jones matrix for antenna p for one  pair. |
| Contains the gains information. Size 2 × 2 | |
| B | Sky brightness distribution matrix, of size 2 × 2. |
| N | Noise matrix, of size 2 × 2. Contains a single |
| realisation n of the thermal noise in each cell. | |
 |
Fourier transform matrix, of size npix × npix. |
 |
Baseline selection matrix, which picks out 1 |
| visibility out of the full set. Size npix × nb | |
 |
npix × npix convolution kernel that defines |
| the PSF. | |
 |
Convolution matrix mapping one δuδv to δlδm. |
The set of all  determines the noise-PSF. |
|
| Size npix × npix. | |
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