cloud cover images as background image.

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jrader
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Posts: 24
Joined: Mon Nov 24, 2003 8:40 pm

cloud cover images as background image.

Post by jrader »

Has anyone tried and had success with using satelite images of cloud cover and then overlayed that with fronts, RCM data, Nexrad III images, isobars and such using either DA2000 or DAW?

If so, what source are you using for satelite images? What do you do to get them in the proper image format? That info would be great as well as whatever else taskwise it takes to accomplish this.
Robert
Junior Member
Posts: 3
Joined: Sun Mar 28, 2004 4:40 pm

Post by Robert »

Yeah, I tried this by saving regular satellite images to .BMP format, and using them as DA backgrounds, and it didn't work out too well. I think satellite data would be a nice addition to DA.

Robert
Wally Mayo
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Location: Roanoke, VA
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Post by Wally Mayo »

I think it would have to be able to generate exact same plot maps areas at the same PROJECTION. I believe older versions had different map projection options, but am not sure.
Then you could supplant the .BMP of a satellite view while still using the .dmf file.
Again, the catch is having not only size, same area, but same projection matching to make it work.
Maybe someone has some other solution.
Fred
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Joined: Tue Nov 25, 2003 4:22 pm
Location: Suoi Tien, Vietnam

Post by Fred »

I use Wxtoimg for receiving APT-satellites. Below an abstract of an article I wrote for the GEO Quarterly (see http://www.geo-web.org.uk).
In the RIG-journal 73 (june 2003) is an article by Thomas Scheelen ( http://www.rig.org.uk ). He uses some modules of David Taylor like HRPT-reader and Groundmap. I did not tried this but I think this can be useful with downloaded files.

Initial
Wxtoimg
Set in <Options/Projections options> the following parameters: latitude, longitude, north, south, west, east, scale. Choose values that will give the image you want. Remove the mark by “disable map overlay”, choose in <Projection> for “Orthographic” and generate the image. Write down the size in pixels (they will appear on the bottom of the screen, just before showing the image), choose <Image/White background> and save the image as BMP.

Digital Atmosphere
Generate a map. Use for latitude and longitude the same values as in Wxtoimg. Use for scale a size that generates more or less the same map as Wxtoimg. It is not so important at this moment. Give width en height the values from Wxtoimg. Generate the map and if it’s ok, save it with <Map/Save map> as BMP.

Fine-tuning
Repeat the next steps until both maps fits exactly.
1.Choose icon “load map” and read the Wxtoimg image.
2.Choose <map/add base map>. This option will project the DA-map over the image and will surely not fit. Now we must try to make the DA-map fit. This is done by making changes in <Map/Generate map/Enter lat/lon.> :
3.Latitude. This will move the map in vertical direction
4.Longitude. This will move the map in horizontal direction.
5.Scale for resizing the map.
6.Make small changes in the steps 3, 4 and 5. After <OK> DA will generate a new map.
7.Continue with step 1.
It can happen that meridians do not fit exactly onto each other. Then you can rotate the image in Wxtoimg by changing the “reference longitude”.

Finishing
Save the DA-map for the last time. This must be done because every lay-out has its own base map and parameter-files. Always open this corresponding map before loading a picture with a different layout from Wxtoimg.

The dimensions of the map can be changed by modifying the “width” in the parameter of Wxtoimg. Give width en height in DA the same values as in Wxtoimg.

Using this you get perfect fitting maps.

Fred van den Bosch
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