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PostPosted: Sun, 26-05-13, 0:45 GMT 
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Thanks John,
I'm trying to show the alignment. These 2 images are of a river in northern Russia.


Basic Rendering Mode specular is off.
Image


OpenGl Vertex Program specular is on.
Image

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PostPosted: Sun, 26-05-13, 1:45 GMT 
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These are images of concern.
The first 2 are above the N60 cutoff. Image 1 has no spec map. Image 2 does.
No Spec
Image

Spec
Image

The next 2 images are on the map that is available here. First one no spec

Image

Spec

Image

There seems to be a lot of areas that probably have water, but the map with no spec shows darker green. Maybe these areas should be dimmed?

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PostPosted: Sun, 26-05-13, 5:56 GMT 
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cartrite wrote:
There seems to be a lot of areas that probably have water, but the map with no spec shows darker green. Maybe these areas should be dimmed?


Not sure about this, but whatever the quality of water (crystal clear or infamous swamp), the intensity of the spec should be the same... (or the quality of water impact it's reflective power? Sounds odd to me...)


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PostPosted: Sun, 26-05-13, 15:23 GMT 
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I'm not sure either.
The way I see it, the total light from the sun can't be hitting the water if it is covered with weeds. So from a vantage point in space, all one would see is the green from the weeds or whatever vegetation is present.

There is another issue. I think these BMNG files were color corrected with a vegetation index for each month. Maybe the raw sat images did show high water reflection in these areas?

There is supposed to be new data being sent down from a new sat called Suomi. Not sure how to access this data. The mission page is here.
http://npp.gsfc.nasa.gov/index.html

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PostPosted: Mon, 27-05-13, 2:11 GMT 
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There is a new dataset for height data. Called GMTED2010 You can access this data from http://earthexplorer.usgs.gov/ but you need to register.

Anyhow, this shows the same water that the specmap does. An image I captured from 3dem of this same area above. What I find funny, is that all water has a value of 0. If it is inland water or ocean, so far it's been 0.?


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PostPosted: Mon, 27-05-13, 4:16 GMT 
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ALL bodies of water are zero ?

odd
lake Superior is about 175-180 M above sealevel, and lake mead is about 330-340 M above sealevel.

Not to mention Lake tahoe at 1900 above sealevel

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PostPosted: Mon, 27-05-13, 6:07 GMT 
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John Van Vliet wrote:
ALL bodies of water are zero ?

odd
lake Superior is about 175-180 M above sealevel, and lake mead is about 330-340 M above sealevel.

Not to mention Lake tahoe at 1900 above sealevel
I thought so too. But after a little investigating, the file I was using had values calculated from the standard deviation of elevation values. That's the only file that has all 0 values for water. The other files in the folders have real values. What I found interesting from that file posted above is that it shows about the same amount of water as the spec map.

With this GMTED2010 data, there are supposed to be 7 files per folder covering the same area but each file calculated a different way. But of the couple of folders I downloaded, most had only 6. There are probably 100 folders. It comes in 3 resolutions. 7.5, 15, and 30 arc seconds. I'm starting to download the 15 arc second files. about 250 meter resolution. It is supposed to be the latest and the greatest.

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PostPosted: Mon, 27-05-13, 6:47 GMT 
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15 arc sec is 240 pixels/degree
that works out to a image of 86400x43200
and 463.8 meters/pixel

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PostPosted: Mon, 27-05-13, 12:42 GMT 
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You are correct. I did/t do the math, I just misread the documentation. The 7.5 data comes to about 250 meters not the 15.
The link to the site is https://lta.cr.usgs.gov/GMTED2010 The other link from a former post is for data access thru Earth Explorer. That link allows access to much more than the GMTED2010.

Edit: For now this mistake you pointed out will work to my advantage. I really only want to update the 86k srtm map we have all been using. I need to figure out how to to turn it into a geotiff file though. 3dem can do it but you need to have enough memory. I don't. I can also create a virtual header file to fool gdal into thinking it's a PDS or ENVI file. Then run gdal_translate. The easiest way though would to start using Linux and install ISIS3.Oh well....
Back to the spec map.
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PostPosted: Mon, 27-05-13, 16:41 GMT 
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as long as there is no need to clean up mismatched sections , like in the map we are all using ( the old one )

i can import it into isis3 rather quickly

but there really would be no need if it is in simplecylindrical
unless it is only +60 to -60 lat

then the poles need fixing

And that will take some time .

am i right in that the data is singed 16 bit in MSB format ( or is it LSB )

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PostPosted: Mon, 27-05-13, 19:18 GMT 
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I believe the GMTED2010 are LSB. And I think the coverage is N90 to S 90. They are not raw binaries though. They are in GeoTiff format.

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PostPosted: Tue, 28-05-13, 13:20 GMT 
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John Van Vliet wrote:

but there really would be no need if it is in simplecylindrical
unless it is only +60 to -60 lat

am i right in that the data is singed 16 bit in MSB format ( or is it LSB )

The GMTED2010 files are LSB. EDIT. I have read this document and found a lot of this post was in error. So Those of you that read this before deletion, I suggest you read this. http://pubs.usgs.gov/of/2011/1073/pdf/of2011-1073.pdf. This will tell all. Sorry if any were misled. I'm getting braindead too. :roll:

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PostPosted: Wed, 29-05-13, 1:16 GMT 
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I've been comparing this to the srtm_ramp2 map I recently downloaded. When I first started this thread long ago, I'm sure I was using a different file. It must have been updated. For this file I just downloaded, I find it to be very similar, probably exact to the GMTED2010 at 15 arc sec. This was in Celestia though. I've yet to look at the actual values in a hex editor for bit comparison.

For the spec map, 2 things still bug me. Water in dessert areas appear unnaturally white and Northern Canada and parts of Northern Europe/Asia have too many water areas on what looks like land and vegetation.

I may have come up with a plan using this new GMTED2010 files to fix those 2 things.
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