Initial sky noise removal

As we have already seen, sky noise can be a dominant noise source in a map, but as long as the sky noise is correlated over the array, it can be removed. One can do this in several different ways, but for a single short integration map one will always use remsky. In the automated SCUBA reduction Jenness et al. [14] use the median option in remsky and include all bolometers. Since we have a centrally symmetric source, we take the second ring, r2, of bolometers using the median option to avoid spikes that may be present in the data.

 % remsky
IN - Name of input file containing demodulated map data 
/@o86_lon_ext/ > 
SURF: run 86 was a MAP observation with JIGGLE sampling of object 
IRC+10216
OUT - Name of output file /'o86_lon_sky'/ > 
BOLOMETERS - The Sky bolometers, [a1,a2] for an array 
/['4','9','29']/ > r2
SURF: Using 12 sky bolometers
MODE - Sky removal mode /'median'/ > 
Sky noise: 0.000602097 (192 points)
Adding mean background level back onto data (value=0.0003676229)

Note that the default behavior of this routine is to add the mean bolometer signal back in to data (this may not be what you wish to do) if it's not then type:

% remsky add=false