Source
1637
1637
robust\*robust and B is dependent on the
1638
1638
noise per visibility estimated. Giving noise='0Jy'
1639
1639
is a not a reasonable option.
1640
1640
In this mode (or formula) robust values
1641
1641
from -2.0 to 0.0 only make sense (2.0 and
1642
1642
-2.0 will get the same weighting)
1643
1643
1644
1644
weighting='superuniform' : This is similar to uniform weighting except that
1645
1645
the total_wt_per_cell is replaced by the
1646
1646
total_wt_within_NxN_cells around the uv cell of
1647
-
interest. ( N = subparameter 'npixels' )
1647
+
interest. N=7 is the default (when the
1648
+
parameter 'npixels' is set to 0 with 'superuniform')
1648
1649
1649
1650
This method tends to give a PSF with inner
1650
1651
sidelobes that are suppressed as in uniform
1651
1652
weighting but with far-out sidelobes closer to
1652
1653
natural weighting. The peak sensitivity is also
1653
1654
closer to natural weighting.
1654
1655
1655
1656
weighting='radial' : Gridding weights are given by ' data_weight \* uvdistance '
1656
1657
This method approximately minimizes rms sidelobes
1657
1658
for an east-west synthesis array.
1706
1707
<description>Number of pixels to determine uv-cell size for super-uniform weighting
1707
1708
(0 defaults to -/+ 3 pixels)
1708
1709
1709
1710
npixels -- uv-box used for weight calculation
1710
1711
a box going from -npixel/2 to +npixel/2 on each side
1711
1712
around a point is used to calculate weight density.
1712
1713
1713
1714
npixels=2 goes from -1 to +1 and covers 3 pixels on a side.
1714
1715
1715
1716
npixels=0 implies a single pixel, which does not make sense for
1716
-
superuniform weighting. Therefore, if npixels=0 it will
1717
-
be forced to 6 (or a box of -3pixels to +3pixels) to cover
1718
-
7 pixels on a side.
1717
+
superuniform weighting. Therefore, for 'superuniform'
1718
+
weighting, if npixels=0 it will be forced to 6 (or a box
1719
+
of -3pixels to +3pixels) to cover 7 pixels on a side.
1719
1720
1720
1721
</description>
1721
1722
<value type="int">0</value>
1722
1723
</param>
1723
1724
1724
1725
1725
1726
1726
1727
<param type="stringVec" name="uvtaper" subparam="true">
1727
1728
<shortdescription>uv-taper on outer baselines in uv-plane</shortdescription>
1728
1729
<description>uv-taper on outer baselines in uv-plane