Currently, three of the JCMT Legacy Surveys have recipes optimized for the goals of the surveys. Support for the others will be added in as timely manner as possible in response to survey input. Picard recipes also exist which replicate the steps performed on the processed data.
The CLS recipe employs a “jack-knife” approach using independent halves of the data in order to estimate and remove residual noise on large spatial scales.
Currently, this recipe works best on single scanned fields (i.e. not a mosaic of multiple fields).
This recipe is very similar to that for CLS with an additional step at the beginning. This step makes maps for each 30-second subscan and calculates the noise level in those maps to determine the noisiest subscans which are ignored by the map-making step. (Note the option exists to use the time-series noise instead.)
For this recipe, it is recommended that the artificial source used to determine the FCF correction be offset from the centre to avoid contamination of the signal.
Processing of SASSy data is focused on detecting compact sources with the aim of following up previously-unknown or interesting-looking detections with more sensitive observations to probe the detailed structure.
Data reduction is tailored to enable the recovery of bright emission on scales up to 480 arcseconds. Data are reduced using a modified bright extended config file and coadded.