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[McIDAS #MHL-637032]: question about imgremap

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  • Subject: [McIDAS #MHL-637032]: question about imgremap
  • Date: Mon, 06 Feb 2006 08:00:37 -0700
Hi Ying,

re:
> Thank you so much for your help!

No worries.

> I found that the generated GeoTIFF file is pure black, and it's only 304.4k
> (it was 23.6MB previously).

It could be that the IMGREMAP invocation line I included was incorrect.
I just changed it to:

imgremap.k NEXRCOMP/4KNTP-NAT GEOTIFF/NEXRCOMP.3 PRO=RECT RES=4 SIZE=ALL

> I used GEMPAK to look at the data, it looks fine. So the GINI data is
> downloaded correctly.


> Do you think it's because of imgremap.k?

I think it might have been my including SSIZE=ALL instead of SIZE=ALL

> It's a pity MERC could not be generated in GeoTIFF, I will try to find
> another way to solve the projection problem.

The McIDAS RECTilinear projection should be a simple Lat,Lon grid, and I as
far as I know, this is the most common projection in GeoTIFF image files.

> Sorry for one more inquery...

No worries.

> I could not set the GeoTIFF's projection correctly in ArcGIS (a commonly
> used GIS).

Hmm...  I believe that SSEC used ArcGIS to test the display of the GeoTIFF
images created by the ADDE GeoTIFF output server.  I will take a look at
one of the images created by the newly modified script in ArcGIS when I get
into work (still at home at the moment).

By the way, after my modification of the ~ldm/mcrunNEXRAD.sh script, the
size of the most recently created GeoTIFF image is 1553933.  Before this
change, it was about 300 KB like you noted.  Can you take a look at the
new images and see if they look OK?

I just looked at the newly created NEXRCOMP0003.tif image in the 
Eye of GNOME 2.10.0 image viewer on my Fedora Core 4 Linux system, and
(aside from coloration), the image looks correct.  So, the image being
created is, at least, a valid TIFF one.

> According to the RECTilinear projection you mentioned, is it the same
> as"Gnomonic" specified at http://www.remotesensing.org/geotiff/proj_list/ ?
> Where can I get further information about its parameters?

I don't think so, but I will need to check with SSEC (or read the source
code) to make sure.

> Thanks again,

Please let me know if the new images are still unreadably by ArcGIS.



Cheers,

Tom
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Ticket Details
===================
Ticket ID: MHL-637032
Department: Support McIDAS
Priority: Normal
Status: Open