[daip] Finding resolution with JMFIT

[Olivia Tang]

Hi,

Thanx for your help last time. I'm trying to use JMFIT and ADDBEAM to
put the resolution onto my MSX pictures. I realize that even adjacent
point sources give pretty different major and minor beam axis in
arcsec and very different position angle. I'm wondering how to select
a sensible value to attach to the picture. And just to make sure, so
you said OHGEO can match the cell size of the 2 pictures. Is that
equivalent to matching the resolution? Thanx very much!

Olivia

On 7/8/05, Eric Greisen <egreisen at nrao.edu> wrote:
> Olivia Tang writes:
>  > 
>  > I have 2 galactic center pictures of 8 micron and 20 cm. Before I can
> start 
>  > the data analysis, I need to match their size and resolution, so that the
> 2 
>  > images can superimpose each other. I would like to know if aips can tell
> me 
>  > what their resolutions are and if there's a program that can transform
> one 
>  > image's resolution to match the other's. As for the size matching, I
> found a 
>  > program called OHGEO. Is it the right thing to use? Thanx for taking your
> 
>  > time to answer my questions.
> 
> OHGEO is good to match not only the cell size but the coordinate
> center and the type of projection.
> 
> The 20cm image will probably have the Clean beam parameters in the
> header - IMHEADER will show, e.g.
> 
> AIPS 1: Conv size=   6.39 X   5.78   Position angle= -10.47
> 
> The optical image probably will not have that information.  You could
> use IMFIT or JMFIT to fit some point sources in the image and
> determine the resolution.  ADDBEAM verb will then let you put that in
> the image header (units are degrees).
> 
> CONVL will smooth an image.
> 
> Eric Greisen
>