20010427: Tom Yoksas

>From: Edward Hindman <address@hidden>
>Organization: CCNY
>Keywords: 200104271758.f3RHwBL11872 McIDAS 

Ward,

>We are making a loop of Global Mollweide images using the ALOOP command.  
>It will not let us load more than five frames:
>
>ALOOP 2350 2354 1 5   This command works
>ALOOP 2350 2355 1 6   This command produces what the first command produced
>
>What am I doing wrong?

Nothing obvious.  Since ALOOP sorts a list of images by time but does
NOT attempt to eliminate duplicates, I have to believe that there are
only 5 images to load, or there are only 5 frames in your session.  Are
you sure that you McIDAS session has more than 5 frames?

>By the way, the files are in Cirrus in the /home/wxnut/mcidas/data/ 
>directory AREA2350 to AREA2357.  

I tried logging onto cirrus as 'mcidas', but the /home/wxnut/mcidas/data
directory is not readable by 'mcidas', so I can't look at the files.  The
reason for this is the permissions on /home/wxnut:

[mcidas@cirrus workdata]$ ls -alt /home
total 28
drwx------    6 wxnut    mcidas       4096 Apr 27 11:38 wxnut

If you could give me the 'wxnut' login or make /home/wxnut (and
/home/wxnut/mcidas and /home/wxnut/mcidas/data) readable by 'mcidas'
I could take a quick look at the files to see if there is anything
obviously wrong.  Again, the ALOOP command you listed above should
work fine.

>Have you been able to "chat" with the SSEC about our IMGCOPY problem with 
>the Mollweide images discussed in your 17 Apr reply to my message?

No, not yet, but I think I understand why one can't do the copy.  A
restatement of what was going on is:

o you want to copy a portion of a Mollweide global IR image into an new
  image with the same projection and blow it up by a factor of two

o since the resolution in the image is set to 1 (an artifact of an IMGREMAP),
  IMGCOPY will not do the copy

The reason that IMGCOPY will not do the copy is that the resulting
resolution would have to be 0.5 ( resolution of 1 / blow-up of two).
The McIDAS AREA format only allows for integral resolutions, so this is
not allowed.

What you are really after, however, is the creation of an image
centered on a certain point but blown up.  You can do this using the
IMGREMAP command.

IMGREMAP RTIMAGES/MOLL-IR MYDATA/IMAGES.1234 LATLON=30 -92 PRO=MOLL RES=15
IMGDISP MYDATA/IMAGES.1234 EU=IMAGE REFRESH='EG;MAP SAT'

The orignal resolution of the image is something like 29.  I chose 15
since this is will result in a blow-up of about a factor of two.

You can play with the RES= keyword and "zoom in" as much or as little as
you want.  For instance, compare:

IMGREMAP RTIMAGES/MOLL-IR MYDATA/IMAGES.1235 LATLON=30 -92 PRO=MOLL RES=8
IMGDISP MYDATA/IMAGES.1235 EU=IMAGE REFRESH='EG;MAP SAT'

You can use the SIZE= keyword on IMGREMAP to adjust how much of the
original image gets remapped into the blown-up copy.

I think that what we _really_ need to do for you is find a source of
higher resolution global composite images that you can use for your
investigations over Nepal.  I know that the images that the Mollweide
composites are created from are higher resolution and are in a
rectilinear projection.  I just blasted off a note to SSEC inquiring
about this.

>Sincerely,

I hope that the IMGREMAP examples above get you going on your project.

Tom