Set various cycle control parameters for
multi-field and wide-field imageing.
Synopsis
setmfcontrol(cyclefactor, cyclespeedup, stoplargenegatives, stoppointmode, minpb, scaletype, constpb, fluxscale)
Description
Control parameters for mosaicing or wide-field imaging which are not
required in single field deconvolution are set here to streamline the
user interface. As multifield and widefield imaging is accomplished
by deconvolution in cycles, many of these parameters control how the
deconvolution cycles are ended.
- cyclefactor: this parameter helps in lowering or increasing the
threshold at which the deconvolution cycle will stop and degrid and
subtract from the visibilities. For very bad PSFs you may want to
reconcile with the visibilties often, thus a larger number is
required here...(4 to 5). For very well behaved data you may want to
deconvolve deep before reconciling: a lower number is used (1.5 to 2.0).
- cyclespeedup: this is used if the PSF is not well behaved and
you want clean to raise by 2 the threshold if it has not reached the
threshold in this number of iteration
- stoplargenegatives: This parameter is exclusively for when using
multiscale clean. This is used to stop the component
search when the largest scale has found this number of negative
components. -1 here means that continue component search even if the
largest component is negative.
- stoppointmode: Again exclusively for when using multiscale
clean. The clean will stop if the smallest scale receives this
number of consecutive components.
- minpb: This is to defined up to what level the voltage pattern
is going to applied when using
setvp. The default is 0.1 of the
primary beam or the voltage pattern defined for the antenna.
- scaletype: This parameter cab be NONE or SAULT. If NONE the
image is not scaled, if SAULT is used the image is weighted so that
the noise is kept uniform across the image. The next two parameters
defines how the SAULT weighting is limited. Obviously then the flux
scale is not uniform across the image. To get the right flux
multiply the image with the fluxscale image.
- constpb: this parameter defines up to what amplitude of the
Primary beam the noise floor is kept uniform, when using SAULT as scaletype.
- fluxscale: use this to give a filename to store the factor image
to apply to the image to get the fluxscale right.
Arguments
| cyclefactor |
in |
Cycle threshold = this * max sidelobe * max resid |
|
|
Allowed: |
Float |
|
|
Default: |
1.5 |
| cyclespeedup |
in |
Cycle threshold doubles in this number of iterations |
|
|
Allowed: |
Float |
|
|
Default: |
-1 |
| stoplargenegatives |
in |
Stop the multiscale cycle for the first n cycles when a negative comp is found on the largest scale |
|
|
Allowed: |
Int |
|
|
Default: |
2 |
| stoppointmode |
in |
Stop multiscale altogether if the smallest
scale recieves this many consecutive components |
|
|
Allowed: |
Int |
|
|
Default: |
-1 |
| minpb |
in |
Minimum PB level to use |
|
|
Allowed: |
Float |
|
|
Default: |
0.1 |
| scaletype |
in |
Image plane flux scale type |
|
|
Allowed: |
String:'NONE'|'SAULT' |
|
|
Default: |
'NONE' |
| constpb |
in |
In Sault weighting the flux scale is constant above this PB level |
|
|
Allowed: |
Float |
|
|
Default: |
0.4 |
| fluxscale |
in |
Names of flux scale images for mosaicing |
|
|
Allowed: |
Vector of strings |
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