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| public:user_software:documentation:ndppp [2020-01-09 14:12] – [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>.antennaconstraint|list|[]|A list of lists specifying groups of antennas that are to be constrained to have the same solution. Example: "[ [CS002HBA0,CS002HBA1],[CS003HBA0,CS003HBA1] ]" will keep the solutions of CS002HBA0 and 1 the same, and the same for CS003.| | |<step>.antennaconstraint|list|[]|A list of lists specifying groups of antennas that are to be constrained to have the same solution. Example: "[ [CS002HBA0,CS002HBA1],[CS003HBA0,CS003HBA1] ]" will keep the solutions of CS002HBA0 and 1 the same, and the same for CS003.| |
| |<step>.smoothnessconstraint|double|0|Kernel size in Hz. When unequal to 0, will constrain the solutions to be smooth over frequency by convolving the solutions with a kernel of the given size (bandwidth). The default kernel is a Gaussian kernel, and the kernel size parameter is the 3 sigma point where the kernel is cut off.| | |<step>.smoothnessconstraint|double|0|Kernel size in Hz. When unequal to 0, will constrain the solutions to be smooth over frequency by convolving the solutions with a kernel of the given size (bandwidth). The default kernel is a Gaussian kernel, and the kernel size parameter is the 3 sigma point where the kernel is cut off.| |
| |<step>.statfilename|string| | File to write the step-sizes to. Form of the file is: "<iterationnr> <normalized-stepsize> <unnormalized-stepsize>", and all solution intervals are concatenated. File is not written when this parameter is empty.| | |<step>.statfilename|string| |File to write the step-sizes to. Form of the file is: "<iterationnr> <normalized-stepsize> <unnormalized-stepsize>", and all solution intervals are concatenated. File is not written when this parameter is empty.| |
| |<step>.uvlambdamin | double | 0 | Ignore baselines / channels with UV < uvlambdamin wavelengths. **Note**: also all other variants of uv flagging described in [[#uvwflagger|UVWFlagger]] (uvmmin, uvmrange, uvlambdarange, etc) are supported (New in 3.1).| | |<step>.uvlambdamin|double|0|Ignore baselines / channels with UV < uvlambdamin wavelengths. **Note**: also all other variants of uv flagging described in [[#uvwflagger|UVWFlagger]] (uvmmin, uvmrange, uvlambdarange, etc) are supported (New in 3.1).| |
| |<step>.subtract | bool | false | Subtracts the corrected model from the data. **NOTE** This may not work when you apply a uv-cut.| | |<step>.subtract|bool|false|Subtracts the corrected model from the data. **NOTE** This may not work when you apply a uv-cut.| |
| | <step>.useidg | bool | false | Do image-based prediction using IDG.| | |<step>.useidg|bool|false|Do image-based prediction using IDG.| |
| |<step>.idg.images|list|[]|Filename of ''.fits'' model images, one per frequency term. The terms are defined as for a polynomial source spectra (not logarithmic), e.g. see [[https://sourceforge.net/p/wsclean/wiki/ComponentList|<step>.idg.regions|string|""|DS9 regions file describing the facets for IDG prediction.| | |<step>.idg.images|list|[]|Filename of ''.fits'' model images, one per frequency term. The terms are defined as for a polynomial source spectra (not logarithmic), e.g. see [[https://sourceforge.net/p/wsclean/wiki/ComponentList/|this WSClean page]]. The frequency in the metadata of the fits files is used as nu<sub>0</sub> in the polynomial evaluation.| |
| /|this WSClean page]]. The frequency in the metadata of the fits files is used as nu<sub>0</sub> in the polynomial evaluation.| | |<step>.idg.regions|string|""|DS9 regions file describing the facets for IDG prediction.| |
| | |<step>.idg.buffersize|int|Based on memory|Set the amount of timesteps that are to be used for each IDG buffer| |
| |<step>.savefacets|bool|false|Write out each facet as a fits file (named facet<N>.fits). Only useful when useidg=true.| | |<step>.savefacets|bool|false|Write out each facet as a fits file (named facet<N>.fits). Only useful when useidg=true.| |
| |<step>.onlypredict|bool|false|Instead of solving, output the predicted visibilities instead. This is useful for testing, although when doing faceted prediction with IDG, it might be fast for certain cases.| | |<step>.onlypredict|bool|false|Instead of solving, output the predicted visibilities instead. This is useful for testing, although when doing faceted prediction with IDG, it might be fast for certain cases.| |
| | <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 ==== |