### REDUCE_SCAN_FAINT_POINT_SOURCES

Process SCAN data from faint compact sources

#### Description:

This is the recipe for processing SCAN data for faint compact sources. The makemap configuration file is tuned to best deal with such data, though the user may specify their own.

Raw data are passed to the map maker which are processed using the blank_field config file to produce an image, which is calibrated in mJy/beam, displayed and tagged as a reduced product. The noise is estimated and the NEFD is calculated. Once all the individual observations have been processed, a coadd is created and displayed. This image is processed with a matched filter to enhance the signal-to-noise ratio of point sources. This image is tagged as a reduced product. The noise properties and NEFD for the new Group image are calculated and written to log files. A signal-to-noise ratio image is created from the matched-filtered image.

Finally, the CUPID task findclumps is run using the fellwalker algorithm to create a source catalogue.

#### Notes:

• If given data from multiple sources, each source will be processed in full in turn.

• The noise level and NEFD are stored in log.noise and log.nefd respectively. The noise and NEFD are calculated for each image as well as for the final coadd (after processing with the matched filter).

• For large amounts of data this recipe will spend a long time not updating the ORAC-DR window. Check to see that makemap is still processing by running top or ps. (Running with -log sf is recommended.)

• Alternative configuration parameters for the iterative map-maker may be specified using the recipe parameters outlined below.

• To reduce the chance of spurious source detections, the group coadd is trimmed to the map size specified in the FITS header before running the source finder. This may not work as intended if the coadd contains maps with different centres.

• The output catalogue, if created will have the extension .FIT. A clump file with suffix _clmp will also be created.

• This recipe can handle data from multiple sources and will correctly coadd maps, taking into account the EXP_TIME and WEIGHTS components.

• This recipe may be called via the shorter name FAINT_POINT_SOURCES.

#### Available Parameters :

##### FINDCLUMPS_CFG
Name of a config file for use with the CUPID findclumps task. The file must exist in the current working directory, $FINDCLUMPS_CONFIG_DIR or$ORAC_DATA_OUT.
##### MAKEMAP_CONFIG
Name of a config file for use with the SMURF makemap task. The file must exist in the current working directory, $MAKEMAP_CONFIG_DIR,$ORAC_DATA_OUT, $ORAC_DATA_CAL or$STARLINK_DIR/share/smurf.
##### MAKEMAP_PIXSIZE
Size of the pixels in the output map. If not specified, the recipe uses the appropriate default value. Note that the timeseries will be downsampled to match this scale during the map-making process.
##### MAKEMAP_REF
Name of a reference image (NDF format) to use to define the output pixel grid. The NDF can be either 2D or 3D and the spatial WCS frame will be extracted.

#### Display

The Frame image is displayed in Gaia window 1. The Group image is displayed in Gaia window 2; its variance is displayed in window 3.