[Qgis-user] Eliminate GAPS SRTM 30 metros
Nicolas Cadieux
nicolas.cadieux at archeotec.ca
Thu Jan 28 05:21:21 PST 2016
Hi,
Thank for that data link. I did not know about it. I am currently doing a PhD on various publicly available DEMs in Canada. My research focuses in Canada because SRTMs are more precise in the north and south (tighter orbit, more data, leaf off). All this is better for the SRTM radar. I should have more results in about one month and I will submit my results for publication. Hopefully, I will also have the latest NASA DEM is my study as they should be publish in June.
So far, SRTM 30 and 90m have about haft the error of aster gdem2. There is not much loss with the 90 m srtm but the 90 m pixel does suffer in mountainous regions. Most of the error from the ASTER data is cause clearly by the tree cover. The SRTM radar has a good vegetation penetration in Canada (leaf off). Aster is made from near infra red images and therefore has no canopy penetration. But radar is generally smother partly because smoothing is part of the data noise reduction in radar images. ASTER has a sharper image resolution even if the pixel size is the same size but this comes at the expense of extra noise.
I will be happy to communicate more result as I get them.
Nicolas Cadieux M.Sc.
Les Entreprises Archéotec inc.
8548, rue Saint-Denis Montréal H2P 2H2
Téléphone: 514.381.5112 Fax: 514.381.4995
www.archeotec.ca
On Jan 28, 2016 02:49, "Thomas Götzelt-2 [via OSGeo.org] " <ml-node+s1560n5247716h57 at n6.nabble.com> wrote:
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Hi,
ALOS World 3D - 30m (AW3D30) data may be also considered an
alternative ( http://www.eorc.jaxa.jp/ALOS/en/aw3d30/ ), for the time
being already available for substantial parts of Southern Asia and
South America. Informations on how resolution and error margins of the
dataset compare to ASTERDEM or SRTM30 will be appreciated.
Cheers
Thomas
Am 27.01.16 um 21:35 schrieb Nicolas Cadieux:
> Hi, Aster gdem are not as good with about 7 m error. They are
> clearly canopy level models. They cover up to 83d and srtm
> are south and north of 60d only. They are more detailed.
> Nicolas Cadieux M.Sc. Les Entreprises Archéotec inc. 
> 8548, rue Saint-Denis Montréal H2P 2H2
> Téléphone: 514.381.5112  Fax: 514.381.4995
> www.archeotec.ca On Jan 27, 2016 2:38 PM, "Carlos Cerdán [via
> OSGeo.org] " < [hidden email] >
> wrote: Hi Eddison: Try r.fillnulls from Processing or directly in
> GRASS. So, we have 30 m SRTMS in http://www2.jpl.nasa.gov/srtm/ .
> It'll be interesting to compare with ASTER GDEM Cheers
> 2016-01-27 13:25 GMT-05:00 Eddison Araya < [hidden email] >:
> <blockquote style="border-left:2px solid #cccccc;padding:0
> 1em" style="margin:0 0 0 0.8ex;border-left:1px #ccc
> solid;padding-left:1ex"> Hola, how eliminate gaps in SRTM
> 30 meters?, in QGIS see no data areas (gaps). Thank you
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