SMURF Update (August 5th 2010)

It's been a couple of months since the last SMURF news entry so I thought I'd bring people up to date.

• All the configuration files for the iterative map-maker have been tweaked and some have been renamed. For example the '_faint' config is now called "dimmconfig_blank_field.lis". We also have a new config file for bright calibrators called "dimmconfig_bright_compact.lis".
• The SMO (time series smoothing) model has been improved. A few bugs have been fixed and it's been parallelized and so is much faster. SMO is not enabled in any of the default configuration files.
• The size of the apodization and padding for the FFTs can now be calculated dynamically based on the requested filter. This is now the default behaviour. A new Fourier filter has also been written that does not require apodization (which may be important for very short maps) but is still being tested.
• Quality handling has been revamped inside the map-maker to allow us to report more than 8 different types of flagging. The report at the end of each iteration is now more compact and if you use the SHOWQUAL command to look at exported models you may see that the bit numbers assigned to a particular quality are no longer fixed. Additionally if more than 8 flags are used the exported model will combine related flags (for example PAD and APOD will be merged into ENDS).
• Very noisy bolometers will now be discarded before the iterative map-maker starts. This can help with convergence. See the "noiseclip" config parameter to adjust this.
• The map-maker now compares flatfield ramps taken at the start and end of each observation and disables bolometers that whose calibration has varied too much. This will not help data taken prior to 20100223 where flatfield ramps are not available.
• The step correction algorithm continues to be improved.
• SC2CLEAN will now report quality statistics in verbose mode.
• SC2FFT can now be given a bad bolometer mask.

The cookbook has also been updated and can be read online.