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Jim Robinson

Freeware Galapagos Mesh?

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Does anyone know of some 38m mesh for the Galapagos Islands? I've found 76m which helps a lot, but would like a bit higher resolution. Also, how about landclass?Thanks,Jim

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I've never found any source data suitable for 38m mesh. I think there may be some land class around. Try searching for SEGS or SEST and you might find some. I see that Google Earth is getting better aerials. I would like to do a shoreline extraction from them, but haven't found a tool yet that can efficiently do that, based on color contrasts.scott s..

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Thanks for the info Scott. I downloaded a SEST scenery package last night and am going to install it right now. I'll keep looking. I had suspected that maybe the lack of mesh was due to a lack of available elevation data. Oh well. Thanks again.Jim

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Hi Scott,you can easily do a shoreline extraction from the SRTM3 v2 data with the help of Jim's Slartibartfast. The newer version of the SRTM data have DTED1-based water body flattening including the oceans. Thus, Slarti can be used to trace the 0-m elevation line. Once you know how Slarti works it takes just a few minutes to generate decent ocean shorelines. Lakes and rivers are a different matter as you first need to create the binary mask for them. Don't know whether Galapagos has many lakes and rivers though...Cheers, Holger

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Thanks Holger. I have Slarti free installed, and I keep saying I am going to start playing around with it, but...My first thought was using Landsat 15m ETM band 5 data. I have some shoreline that I did, and while it is more accurate than the default, it has a lot of "stair step" artifacts that look unnatural at low altitude. I tthnk maybe Slarti has some smoothing it can do, though (or maybe that is the pay version only). But looking at the Google Earth data, that is much higher resolution than you will get from sampling the SRTM data. Here is my current "state of the art" which you can see is kind of crappy. It's probably better in FSX but haven't looked there yet. I have some personal interest in this because my Dad was an aircraft mech / flight engineer in WWII with the PBM-3 Mariner flying boats, and he spent some time here with a detachment from their home base of NAS Coco Solo CZ.http://forums.avsim.net/user_files/169452.jpgscott s..

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Hi Scott,indeed, the SRTM3 water data has ~90-m resolution so if you have a cloud-free Landsat image you should be able to derive a more detailed 30-m or even 15-m (Band 8) water mask for the Galapagos.Below is the download link with are files from a quick test this morning using SRTM3 v2 data and my standard Slarti algorithm. The screenshots show the difference between default and the Slarti output. http://www.hsandmann.com/files/Galapagos_Slarti_test.zipTo install properly requires deactivating the corresponding AP, FL, HP, and HL *923310.bgl and *923320.bgl files in scenerysamescenery.Obviously, the files need some clean-up and edits. For example, SEGS appears to be misplaced in the default data and would have to be repositioned. Also, some land class work is needed to fill in islands that are all water with the Slarti data. Finally, I tend to use a custom, "feathered" shoreline texture, which looks much better than the straight-edged default options (and the shoreline vectors themselves need some clean-up in SBuilder due to the endpoint "hooks" that Slarti inserts erroneously).Anyway, feel free to use the files if you find them helpful. I've included my Slarti .inf file for reference.Cheers, Holger http://forums.avsim.net/user_files/169458.jpghttp://forums.avsim.net/user_files/169459.jpghttp://forums.avsim.net/user_files/169460.jpg

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Thanks -- I will have to go back to work on it. I have a modified SEGS and landclass done already.scott s..

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