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Data selection

CLIC will draw one box for each x,y,antenna (or baseline), sideband, baseband or IF or spectral window or polarisation. Each criteria can be used to define a group or many groups of a value. For example SET BBAND 1 TO 2 will create one baseband group containg basebands 1 and 2. SET BBAND 1 2 TO 4 5 AND 6 AND 8 will create 3 basebands groups containing baseband 1, basebands 2, 3, and 4, and basebands 5, 6 and 8. A box will be created for each antenna or baseline, sideband and each of the 3 groups.

Figure 4: Example of CLIC plot. The red rectangles are not part of the original plot and were added to ease identification.

SET ANTENNA or SET BASELINE may be used to specify whether to plot per antenna or per baseline and can be used to plot only a subset of what is in the file. The corresponding antenna or baseline is shown in the left box header of the box (red rectangle number 1 in Fig. 4)

SET SIDEBAND is used to control which sidebands to plot. The corresponding sideband is shown in the right header of the box (red rectangle number 3 in Fig. 4).

SET BBAND, IF, SPW, POL are used to control how the data are selected. Selecting according to any of these criteria will also select the corresponding control parameter. For example SET BB 1 will automatically select the corresponding IF, spectral windows and polarisation. The corresponding value is shown in the central header of the box (red rectangle number 2 in Fig. 4).

Both metadata and data can be plotted. The metadata may have a physical origin at a specific point in the signal transport or the hardware, hence have a natural dependency on baseband, IF, or spectral window, so will be selected according to that criteria, and averaged if the group has more than one value.

For data, there are both "continuum" and "line" data in the IPB files (see section 3.3.2). Depending on how the spectral windows are selected, continuum (SET SPW C1) or line (SET SPW L1) will be used. In case the line data are used, the selection of the phase-corrected spectral dump or uncorrected spectral dump (both are stored in the IPB file) is done according to the SET PHASE ATM$ \vert$ NOATM selection. The actual use of phase-corrected data is also conditionned by the validity of the phase correction, which is normally checked on the nearest calibrator. For the phase-corrected to be selected on a baseline requires a valid correction for both antennas.


next up previous contents index
Next: Averaging Up: Plotting Previous: Plot selection   Contents   Index
Gildas manager 2022-01-17