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| public:user_software:documentation:ndppp [2020-02-11 16:03] – [DDECal] André Offringa | public:user_software:documentation:ndppp [2020-05-28 18:53] – [SetBeam] André Offringa |
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| * **[[#H5ParmPredict]]** to subtract multiple directions of visibilities corrupted by an instrument model (in H5Parm) generated by DDECal. | * **[[#H5ParmPredict]]** to subtract multiple directions of visibilities corrupted by an instrument model (in H5Parm) generated by DDECal. |
| * **[[#ApplyBeam]]** to apply the LOFAR beam model, or the inverse of it. | * **[[#ApplyBeam]]** to apply the LOFAR beam model, or the inverse of it. |
| | * **[[#SetBeam]]** to set the beam keywords after prediction. |
| * **[[#ScaleData]]** to scale the data with a polynomial in frequency (based on SEFD of LOFAR stations). | * **[[#ScaleData]]** to scale the data with a polynomial in frequency (based on SEFD of LOFAR stations). |
| * **[[#Upsample]]** to upsample visibilities in time | * **[[#Upsample]]** to upsample visibilities in time |
| | <step>.invert | bool | **true** | Invert the beam. When applying the beam to transfer calibration solutions, this should be true. In other words: ''invert=true'' means correcting for the beam, ''invert=false'' means corrupting with the beam. When using the beam in a predict (or gaincal) step, this option defaults to ''false'' (so it will corrupt for the beam). | | | <step>.invert | bool | **true** | Invert the beam. When applying the beam to transfer calibration solutions, this should be true. In other words: ''invert=true'' means correcting for the beam, ''invert=false'' means corrupting with the beam. When using the beam in a predict (or gaincal) step, this option defaults to ''false'' (so it will corrupt for the beam). | |
| | <step>.beammode | string | "default" | Beam mode to apply, can be "array_factor", "element" or "default". Default is to apply both the element beam and the array factor. | | | <step>.beammode | string | "default" | Beam mode to apply, can be "array_factor", "element" or "default". Default is to apply both the element beam and the array factor. | |
| | |
| | ==== SetBeam ==== |
| | SetBeam is an expert option and should only be used in rare cases. It allows direct manipulation of the beam-keywords for a column in a measurement set. Normally, DP3 registers whether the visibilities in a column are corrected for a beam or not, and if so, in what direction the beam was corrected for. This avoids incorrect corrections / scaling by the beam. However, certain actions can change the scaling of the visibilities without that the beam keywords are changed, in particular when predicting (either with DP3 or with another tool). When predicting a single source and not applying the beam, the visibilities are 'corrected' for the beam in the direction of the source. Under those circumstances, SetBeam can be used to modify the beam keywords. In that case, set ''direction'' to the source direction and ''beammode'' to default. |
| | | <step>.type | string | | Case-insensitive step type; must be 'setbeam' | |
| | | <step>.direction | string vector | [] | A RA/Dec value specifying in what direction the beam is corrected. | |
| | | <step>.beammode | string | "default" | Beam mode to apply, can be "array_factor", "element" or "default". Default means that sources in the given direction have corrected (intrinsic) flux values, i.e. they are corrected for the full beam. | |
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| ==== UVWFlagger ==== | ==== UVWFlagger ==== |