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20041026: Tips about satellite imagery manipulation thru McIDAS

>From:  David Garrana Coelho <address@hidden>
>Organization:  UFRJ
>Keywords:  200410270121.i9R1LxvV009497 McIDAS

Hi Daveid,

>       How are you?

I am quite busy this week; I am conducting a training workshop for
McIDAS, and I have to write two papers and create a PowerPoint
presentation.

>I'm writing just to make a quick question. I'm 
>spending some time with my old McIDAS scripts which generate the images 
>for our site, and I managed to fix, for example, the low contrast problem 
>with Water Vapor images using the EU command. I studied the IMGOPER, 
>IMGOLAY and FRMOLAY commands trying to generate something like that:
>
>       http://www.osei.noaa.gov/OSEIiod.html

OK.

>       It appears they are using McIDAS, but how did they manage to 
>attribute each band (CH1, CH1 and CH4 or VIS, VIS, IR) to Red, Green and 
>Blue values separatedly, within the same image? Any clues or tips on that? 

If they used McIDAS, they would would accomplish the creation of a true
color display using the COMBINE command.

>This type of image would be a valuable asset to our site, besides being 
>really beautiful. The images who overlay TOPO and IR/VIS are also 
>very interesting.

The VIS/IR/TOPO images are easy to create. The ones that combine
three different satellite bands (wavelength channels) are also easy
to create, but typically use bands different from what are available
from GOES.  Even still, I suggest you try creating a true color
display using the VIS (band 1), short wavelength IR (3.9 um), and
thermal IR (10.7 um) bands and see what they look like.  After creating
a composite using COMBINE, then next important step is using an
enhancement that really shows the image well.

>       The Training Workshop Documentation at Unidata page helped me 
>understand a little the IMGOPER command (and make it work), but I haven't 
>managed yet how to use IMGOLAY/FRMOLAY with satellite/satellite composites 
>(I'm not even sure if the aforementioned products are generated thru these 
>commands)

The IMGOLAY and FRMOLAY commands are used for overlaying information
from one image on top of another.  The most useful example of this
that I have seen is overlaying radar echos from one image on top
of a satellite image.  IMGOLAY/FRMOLAY are not useful in creating
displays like the one shown in the URL you list above.

>       If you happen to have any examples I could look upon and adapt to 
>our needs that would be very useful, just to guide me.

Please take a look at the online help for COMBINE and give it a try.
If this is not the thing you are looking for, I will show you an
example of overlaying radar echos on a satellite image using FRMOLAY.

Cheers,

Tom
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* Tom Yoksas                                             UCAR Unidata Program *
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