[talk-ph] ASTER GDEM is now released for civilian use!

[maning sambale]

A quick gdal_contour and qgis overlay.  As expected, both data (SRTM
and ASTER GDEM V2) not useful for high-rise urban areas.
http://www.flickr.com/photos/esambale/tags/srtmaster/

On Sat, Oct 22, 2011 at 10:30 PM, maning sambale
<emmanuel.sambale at gmail.com> wrote:
> On my list.
>
> I also have to do an evaluation of the SRTM's 30m resolution.  Some
> are also available for the PH.  Will check if this is available in the
> public.
>
> On Sat, Oct 22, 2011 at 10:20 PM, Eugene Alvin Villar <seav80 at gmail.com> wrote:
>> Hi maning. Well, why don't you do your evaluation again for V2? It's
>> supposed to be much more improved than v1 since they collected a lot
>> more data. :)
>>
>> On Sat, Oct 22, 2011 at 10:05 PM, maning sambale
>> <emmanuel.sambale at gmail.com> wrote:
>>> We had an internal evaluation of this dataset (v1) a while back, it
>>> has a several data issues such as too much noise, molehills and
>>> unknown depressions in our test area.
>>>
>>> We concluded that as per V1, it is better to use the SRTM dataset.
>>>
>>> And another thing consider:
>>>
>>> "To let people know before they spend a lot of time downloading the new
>>> ASTER GDEM: this new data has a grid spacing of 1 arcsecond (~30 m), but
>>> the actual resolution is closer to about 120 m because they used a 9x9
>>> pixel matching window on the ASTER 15 m images to extract the
>>> topography. The resolution and accuracy in most locations is not as good
>>> as the SRTM 3-arcesecond DEM, but it does have useful data in many of
>>> the locations where SRTM has voids."
>>>
>>> I don't know if this has improved already for V2.
>>>
>>>
>>> On Sat, Oct 22, 2011 at 9:27 PM, Eugene Alvin Villar <seav80 at gmail.com> wrote:
>>>> Hi guys,
>>>>
>>>> Exciting map geek news! Version 2 of the ASTER GDEM data[1] has just been
>>>> officially released for civilian use![2]
>>>>
>>>> Some of you may have been aware of the ASTER GDEM map data that was released
>>>> back in 2009 (Version 1). This data contains the 3D elevation of 99% of the
>>>> earth at a resolution of 30 meters. This is 9 times more dense than the
>>>> SRTM3 data (90m resolution) that is the default data used in Google Earth.
>>>> However, version 1 was only released as raw data only fit for scientific
>>>> research. In version 2, they have clean the data and it can now be used by
>>>> the general public. :)
>>>>
>>>> I once played with GTOPO30 and SRTM3 data to create topographic maps[3] and
>>>> I think the ASTER data would be interesting to play around with. :)
>>>>
>>>> [1] http://www.gdem.aster.ersdac.or.jp/
>>>> [2] http://www.wired.co.uk/news/archive/2011-10/19/nasa-elevation-map
>>>> [3] http://vaes9.codedgraphic.com/posts/topomaps_using_srtm3_data
>>>>
>>>
>>> --
>>> cheers,
>>> maning
>>
>
>
>
> --
> cheers,
> maning
> ------------------------------------------------------
> "Freedom is still the most radical idea of all" -N.Branden
> wiki: http://esambale.wikispaces.com/
> blog: http://epsg4253.wordpress.com/
> ------------------------------------------------------
>



-- 
cheers,
maning
------------------------------------------------------
"Freedom is still the most radical idea of all" -N.Branden
wiki: http://esambale.wikispaces.com/
blog: http://epsg4253.wordpress.com/
------------------------------------------------------