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imager.setsdoptions - Function

2.3.1 Set some options for single dish processing


Description

Various less-often-used options for single dish processing can be set.

scale
The overall scale of the single dish data is multiplied by this factor.
weight
The weight given to the single dish data in the imaging is multiplied by this factor.
convsupport
This parameter can be used to change the support used in gridding single dish data in imaging. If ’PB’ or ’pb’ is used as the ’convtype’ in setoptions this parameter is ignored as the support is defined by the primary beam. The deafult of -1 mans 1 as convsupport is used for ’box’ convolution function and 3 is used for ’SF’ convolution function.
pointingcolumntouse
This parameter is NOT to be changed under normal circumstances. This is to be used by those who know what they are doing and want to try to use different columns in the POINTING table especially if they believe their dish direction is wrong. And if any of the _OFFSET columns is used do not expect to be able to use a different frame in the image setup in defineimage. Possible values are DIRECTION, TARGET, ENCODER, POINTING_OFFSET, SOURCE_OFFSET
truncate
The truncation radius as a quantity or a float value. This parameter is effective only when ’GAUSS’ or ’GJINC’ is used as the ’convtype’ in setoptions. You can use an unit ’pixel’ to specify truncation radius as pixel value. If float value is set, or quantity without unit is set, its unit will be ’pixel’.
gwidth
The width of the gaussian beam as a radius of half maximum. This parameter is effective only when ’GAUSS’ or ’GJINC’ is used as the ’convtype’ in setoptions. You can use an unit ’pixel’ to specify truncation radius as pixel value. If float value is set, or quantity without unit is set, its unit will be ’pixel’. Note that, when ’GJINC’ is used as the ’convtype’, gwidth doesn’t directry specify width of the convolution function.
jwidth
The witdh of the jinc beam as a parameter c, where jinc = J_1(pi*x/c)/(pi*x/c). This parameter is effective only when ’GJINC’ is used as the ’convtype’ in setoptions. You can use an unit ’pixel’ to specify truncation radius as pixel value. If float value is set, or quantity without unit is set, its unit will be ’pixel’. Note that jwidth doesn’t directly specify width of the convolution function.

Arguments





Inputs

scale

Scaling applied to single dish data

allowed:

double

Default:

1.0

weight

Weights applied to single dish data

allowed:

double

Default:

1.0

convsupport

number of pixel for convolution support

allowed:

int

Default:

-1

pointingcolumntouse

Which Pointing Table column to use to get direction

allowed:

string

Default:

DIRECTION

truncate

truncation radius (effective only for ’GAUSS’ or ’GJINC’)

allowed:

any

Default:

variant -1pixel

gwidth

radius of half maximum for gaussian (effective only for ’GAUSS’ or ’GJINC’)

allowed:

any

Default:

variant -1pixel

jwidth

c-parameter for jinc function (effective only for ’GJINC’)

allowed:

any

Default:

variant -1pixel

minweight

Minimum weight level to use for weight correction and weight based masking.

allowed:

double

Default:

0.

clipminmax

Clip minimum and maximum values from each grid

allowed:

bool

Default:

false

Returns
bool

Example

 
 
- im.setsdoptions(scale=1.0, weight=1.0, convsupport=5)  
 

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