### COM.SIG_LIMIT

Controls the rejection of time slices with inconsistent common-modes

#### Description:

This value is only used if data from more than one sub-array is being included in the map, and parameter "com.perarray" is zero, causing a single mean COM model to be used for all sub-arrays. In such cases, if the common-mode signals estimated from the individual sub-arrays show significantly different structure, subtracting a mean COM model will leave large residuals in the bolometer time streams. If a FLT model is being used, the high pass filter will remove much of this residual signal, but any high frequency component will remain, often causing strong " blobs" in the map.

The COM model can identify and flag time slices where the individual common-mode signals appear to be significantly different to the mean common-mode signal. The individual common-mode signals are first high-pass filtered using the same filter as the FLT model. At each time slice, the mean and standard deviation of the remaining high frequency common-modes are found. The RMS of these standard deviations, taken over the whole time stream, is then found. All bolometers within individual time slices for which the standard deviation exceeds " com.sig_limit" times the RMS value are flagged in all sub-arrays, causing them to be excluded from the FLT model and the map. Note, this flagging process is performed from scratch on each iteration - that is, samples flagged on a previous iteration are tested again on each subsequent iteration and may be " unflagged" if the differences between individual common-mode signal become smaller.

Setting this parameter to 3 is a good starting point. Setting it to zero (the default) causes this consistency filter to be skipped. See also parameter "com.sig_wing" . [0]

Type:
real

#### SMURF Usage

SC2CLEAN, MAKEMAP, CALCQU