PCA.NOISELIM

Controls the determination of multiple background signals

Description:

This parameter gives the smallest allowed noise level after removal of the PCA model. If the removal of the PCA model causes the noise in a bolometer to fall to lower than " pca.noiselim" times the noise level it had before removal of the PCA model, then the bolometer is flagged as bad until the next iteration. This usually happens for bolometers that appear to be " unique" for some reason (i.e. look completely unlike other bolometers). In such cases one of the PCA components will be nearly identical to the bolometer, and so leave no significant residuals after subtraction of hte PCA model. Note, this parameter should normally be set to zero if the PCA model occurs before the COM model within pareameter " modelorder" . This is because the PCA model will then remove the typically huge common mode, resulting in an apparent huge fall in noise in all bolometers. This would cause all bolometers to be rejected if the default value is used for pca.noiselim. [0.1]
Type:
float

SMURF Usage

MAKEMAP, CALCQU