1 read beam demo
2 read dirty demo
3 clean ?
4 hogbom /flux 0 1
5 show residual
6 show clean
7 write clean demo
8 let name demo
9 show noise
10 let ares 0.5*noise
11 clean ?
12 hogbom /flux 0 1
13 let niter 2000
14 clean ?
15 hogbom /flux 0 1
16 show residual
17 show clean
18 for iplane 1 to 10
19 show clean iplane
20 support
21 hogbom iplane /flux 0 1
22 write support "demo-"'iplane'
23 next iplane
24 show residual
25 view cct
26 view clean
27 write residual demo
28 write clean demo
29 write cct demo
Comments:
- Steps 1-2
- Read dirty beam and dirty image from the
demo.beam and
demo.lmv files. Those steps are not
needed if the dirty beam and image are already stored in the internal
buffer, i.e. if you have imaged the uv table just before in the same
IMAGER session.
- Steps 3-6
- Print the current state of the control parameters,
deconvolve the dirty image using the
HOGBOM algorithm (step 3) and
look at the results (residual and clean images). The
/flux 0 1
option pop-up the visualization of the cumulative flux deconvolved as the
clean components are found.
- Steps 8-12
- Estimate the empirical noise through the
SHOW NOISE
command after this first deconvolution and set the ares stopping
criterion accordingly. Check that the new value of ares has been
correctly set (step 11) and restart deconvolution.
- Steps 13-17
- Increase the number of clean components as the previous
deconvolution stopped before the residual image reached the
ares value. Restart deconvolution and look at results.
- Steps 18-23
- Attempt to improve deconvolution by definition of a
support per plane and deconvolve this plane accordingly. The support is
stored in a file for further re-use. The deconvolution results are then displayed.
- Steps 24-26
- Display the residual images, visualize the cumulative
flux as a function of the clean component number and visualize the clean
spectra cube in an interactive way.
- Steps 27-29
- Write residual image, clean image and clean component
list in
demo.lmv-res,
demo.lmv-clean and
demo.cct files for later use.
Typical deconvolution session using other CLEAN algorithm would look
very similar. The main difference would be the possible tuning of other
control parameters. A deconvolution session using
MX would start
differently as the imaging and deconvolution are done in the same step:
1 read uv demo
2 mx ?
3 mx /flux 0 1
4 show residual
5 show clean
6 write * demo
% 6 write beam demo
% 7 write dirty demo
% 8 write clean demo
% 9 write residual demo
% 10 write cct demo
Comments:
- Step 1
- Read the demo.uvt uv table in an internal buffer.
- Step 2
- Check current state of the variables that control the
imaging and deconvolution.
- Steps 3-5
- Deconvolve and look at the results.
- Steps 6-10
- Write all the internal buffers on disk files.
All the tuning of the typical imaging and deconvolution sessions could be
used in this
MX session although they are not repeated here.