Some reductions of SCUBA-2 data exhibit arc-like structures, most often in “blank field” observations taken in good weather and at high elevation. An example reduction of a group of observations exhibiting this issue can be seen below, along with an alternative reduction where it has been suppressed by altering the dimmconfig parameters.
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| Example reduction showing the issue with the standard blank field config. | Reduction of the same data with reduced filt_edge_largescale parameter |
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Please see the investigation of parameters to suppress noise arcs for more detailed information about this issue. There you can find example reductions made with varying parameters in blank field and more typical flt-based configurations. But in summary, modifying the blank field config. to reduce the filt_edge_largescale parameter, as in the configuration below, may be sufficient.
^$STARLINK_DIR/share/smurf/dimmconfig_blank_field.lis filt_edge_largescale = 125