After we calibrated the maps and done the baseline removal, we need to restore the map from a dual to a single beam map. This is done by using restore. This task does a standard EKH restoration. Below we show an example of restoring a scan map of NGC7538, a high mass star forming region. In this case we accept the default for the chop throw, but if the restored map looks poor, it is most likely because the chop throw deviates from the nominal value.
% restore IN - Name of input file containing demodulated data /@n39_lon_rlb/ > SURF: run 39 was a MAP observation of object NGC7538 CHOP - Size of chop /60/ > SURF: file contains data for 8 exposure(s) in 2 integration(s) in 1 measurement(s) OUT - Name of file to contain restored data /'n39_lon_res'/ > 2POS_DECONV: Processing exposure 1 of integration 1 ........... SCULIB_2POS_DECONV : no data for exp 8 in int 1, meas 1 2POS_DECONV: Processing exposure 1 of integration 2 .......... 2POS_DECONV: Processing exposure 7 of integration 2 SCULIB_2POS_DECONV : no data for exp 8 in int 2, meas 1
Once this is done, we can apply pointing corrections to remove any pointing drifts we had during the duration of the map. If the map is still uncalibrated (we strongly recommend to apply calibration immediately after the extinction correction), we should do it now. Once we have all the maps calibrated we can proceed and co-add any additional maps that we may have using rebin, exactly like we do for jiggle maps. Note that if you co-add data sets taken in different weather conditions or during different nights, you will have to weight the individual data sets in order to minimize the noise in your final map.
The SCUBA map reduction cookbook