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public:user_software:documentation:ndppp [2020-05-28 18:52]
André Offringa
public:user_software:documentation:ndppp [2020-05-28 18:53] (current)
André Offringa [SetBeam]
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 ==== SetBeam ==== ==== 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, use direction ​for the source direction and beammode to default.+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>​.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>​.direction | string vector | [] | A RA/Dec value specifying in what direction the beam is corrected. |
  • Last modified: 2020-05-28 18:53
  • by André Offringa