[daip] Re: AIPS MR clean question

[Eric Greisen]

Eric Miller writes:
 > Hi Eric,
 > 
 > I have a question about using using IMAGR to do multi-resolution cleaning, 
 > and it appears you're the one to ask.
 > 
 > It appears that using MR in IMAGR does a great job, even better than Bart 
 > Wakker's version that I had been using (in MIRIAD).  I'm a bit confused 
 > about the output, though.  I get a number of cleaned images equal to the 
 > number of Gaussians (resolutions) at which I clean, which makes sense, 
 > since IMAGR treats them as separate fields.  So if I have NGAUSS=3 and 
 > WGAUSS=0 60 120, I get three images:
 > 
 > AIPS 1:   23   20 M83         .ICL001.    5 MA 22-JUN-2004 13:39:32
 > AIPS 1:   24   20 M83         .ICL002.    3 MA 22-JUN-2004 13:35:16
 > AIPS 1:   25   20 M83         .ICL003.    2 MA 22-JUN-2004 13:35:26
 > 
 > Which of these has the final, fully cleaned image?  I'm assuming it's 
 > ICL001, which is at full resolution, and since I'm using OVERLAP=2 I 
 > believe (correctly?) that it contains all the components found at every 
 > resolution.  Are the other images just the cleaned maps with components at 
 > 60 or 120 resolution, or residual maps at those resolutions?  There's not 
 > very much signal in them, which is why I'm not sure.
 > 
 > The ICL001 map looks very good, I just want to make sure I don't need to 
 > combine these all in some way to get the final map.

The ICL001 image is the only one to use - the others are in fact
residual images.  I could see no way to make use of them at the end.
If I added all the components back at their correct resolution then
they would all be similar except the ICL002 and ICL003 would have
different - misleading - noise characteristics.

I'm glad that it is working well.

Eric Greisen