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crashaz
July 1st, 2009, 16:57
http://www.nasa.gov/topics/earth/features/aster-20090629.html

:icon_lol:

MaskRider
July 2nd, 2009, 03:28
Hiya James!

ASTER is indeed one heck of a technological achievement. My congratulations to NASA and Japan's Ministry of Economy, Trade and Industry (METI).

However, unless ASTER shows me ants dancing jigs on the jungle floor next to the perfectly defined details of long overgrown and forgotten WWII airfields Rhumba's SRTM based mesh/mask offering is what I will stick with. :d

Rhumba's mesh/masks finish up- spectacularly IMHO- the part of the CFS2 PTO that MS originally delivered unfinished.

So I will tweak my PI, Formosa, and DEI airfields to fit this mesh- and add some new airfields, too, now that there is a nice canvas on which to build. The only concession I will make to ASTER is to perhaps use ASTER data- when a cleaned up copy becomes available- to tweak the fit of very localized locations from time to time.

rhumbaflappy
July 2nd, 2009, 08:25
Hi Crashaz.

Here's a thread with my take on this:

http://www.fsdeveloper.com/forum/showthread.php?t=15992#post103506

I'm not alone... now I'm reading some opinions that the SRTM3 90 meter data we've been using is actually more precise than this raw 30 meter ASTER data.

It will take 4-5 years before this data is cleaned up, and might not be better than what we already have.

What would be good is if they released a cleaned-up version of the world 30 meter SRTM. Our 90 meter data is a dumbed-down version of the original 30 meter... all data from the shuttle was 30 meter. Maybe the release of the 30 meter ASTER will convince the US that free 30 meter SRTM data no longer poses a security risk.

Dick

crashaz
July 2nd, 2009, 12:13
Hey good to hear from you guys.!.. my first thought in this post was that ASTER would help fill in the SRTM bad spots.

I have been neglecting my groundpounding studies lately... so I am going to run over and read the thread you posted Rhumba.

I am sure I will see the light then. :wavey:

rhumbaflappy
July 2nd, 2009, 17:13
Hi Crashaz.

I'm going to try to "fix" some of the ASTER data.

I'll take CGIAR SRTM 90 meter data, shift the pixels SE 1/2 pixel ( error in CGIAR implementation ), resample that to 30 meter data, add sea level.

I then take the SWBD ( SRTM water flattens ) and apply them to the ASTER data, giving me pretty good sea level.

Then I'll binary compare the sea-leveled ASTER data to the shifted SRTM data... if the ASTER is within 100 meters of the same elevation for each point, I'll write a new file ( signed 16-bit ) with the ASTER data. If the point is greater than 100 meters difference, I'll use the resampled SRTM data point in the new file.

The end result should be a new 1x1* signed 16-bit, waterbody flattened, raw DEM ( with holes, spikes, and clouds corrected ).

Maybe... :confused:

Dick

crashaz
July 2nd, 2009, 18:29
That reminds me... someone asked in an email about vector (roads, shorelines, rivers) data that matches up well with the SRTM data. Any ideas Rhumba on which direction we should go for vector data? :wavey:

rhumbaflappy
July 2nd, 2009, 19:38
Vector data is tough... there really are no good shorelines. Tiger data for the US is good for roads.

Imagery isn't so bad. LandSat7 is good, and of course the GoogleMap, BingMap, YahooMap trio is OK.

If it was easy, everyone would have already done it.

Dick

crashaz
July 6th, 2009, 09:07
True enought that. LOL!

Ok looks like he will have to go about it the old fashioned way. Does CFS3 work with the Ground2k methods? I can't remember that far back whether CFS3 uses the same vector programming as FS9 or CFS2?