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Baseline versus Antenna based calibration

Although many of these calibration parameters are antenna based, CLIC is able to keep simultaneously two values for these parameters: an antenna-based value and a baseline-based value. Whenever an antenna-based calibration function is computed (i.e. a part of the $A_i$, or of the $S_{ij}$), CLIC offers the possibility of solving for an antenna-based or a baseline-based function. In general, solving for antenna based parameters should be preferred, since this mode offers less free parameters (so that they are better constrained) and uses a priori knowledge of the instrument (e.g. the phase closure relations). However, in some cases, well-identified baseline-related problems make it difficult to calibrate in antenna-based mode, so it may be needed to look for baseline-based solutions, mainly for amplitude or phase calibration.

Gildas manager 2018-03-23