Except resolution of 30 meters, How far is the ASTER DEM accurate for the mapping, for morphometric analysis or any other purpose of study, over SRTM DEM?
I used GDEM ASTER and in some conditions as glacier areas and forest areas there are some problems of accuracy if you want to extract contour lines or use in accurate hydrology analysis; for a better using in geomorphometric analysis It is better to preprocess with a "low-pass" filter and with a final map accuracy lower than 30 mt; you can find also an interesting discussion in http://cdn.intechopen.com/pdfs-wm/32991.pdf
Dear Kanchan,
it is important to note that the effective resolution of the ASTER GDEM is far below the posting of 30 m. We have compared different DEMs for a study site in a high mountain environment in SE Tibet (currently under review in Geomorphology) and found that the ASTER's data quality is widely inferior to SRTM, particularly to the new 30 m version of SRTM. Specifically, ASTER suffers from abundant bumpy artifacts and local blunders (the latter originating from clouds in the base data), strongly exacerbating geomorphometrical incestigations. This may, however, be different for other study areas with less pronounced relief, cloud cover, etc.
Here are some papers that might be interesting for your investigations:
http://dx.doi.org/10.1109/IGARSS.2011.6050017
http://www.jspacesystems.or.jp/ersdac/GDEM/ver2Validation/Summary_GDEM2_validation_report_final.pdf
http://www.jspacesystems.or.jp/ersdac/GDEM/ver2Validation/Appendix_A_ERSDAC_GDEM2_validation_report.pdf
http://dx.doi.org/10.1029/2008GL035036
Bolten and Bubenzer (2006):
http://www.schweizerbart.de/publications/detail/isbn/9783443211424/Zeitschr_f_Geomorphologie_Suppl_Bd_1
http://dx.doi.org/10.1080/01431160802167949
http://dx.doi.org/10.1016/j.geomorph.2009.05.010
http://dx.doi.org/10.1016/j.geoderma.2013.08.023
Hope this helps.
Best,
David
We are using it for analysis up to 1:25000 scale topo map analogs. The vertical accuracy not bad (3 - 10m)
Dear Kanchan,
We have also compared different DEMs in a high mountain environment (http://www.sciencedirect.com/science/article/pii/S1674987114000036) as well as in a less rugged, midlands (http://link.springer.com/article/10.1007/s12665-014-3478-0) in the southern Western Ghats, India and the results of both the studies disclosed that SRTM DEM (v. 4.1) have better positional accuracy over ASTER GDEM (v.2.0). In both conditions, SRTM data have better performance over ASTER GDEM. In order to understand the effects of DEM data on morphometry, we then performed a morphometric analysis for the midland basin (http://www.tandfonline.com/doi/abs/10.1080/10106049.2014.955063#.VOxCDvmUcgs) which also supports the use of SRTM data for basin morphometry. In general, several studies suggested SRTM data over ASTER GDEM (please search the literature/cross references in the articles). I also agree with David Loibl that the observations from our study area may not be true for your area, but depends on several factors such as topography, vegetation type and density, cloud cover, extent of waterbodies etc.
For small areas unfortunately not. SRTM should be better but be careful for the artefacts. They can prodece quite a mess especially in morphometric analyses.
You could check this:
http://www.esoter.net/content/srtm-dem-processing-and-elimination-artefacts
It depends. In hilly terrain ASTER dem has error. Some time river channer can be shifted more than 500 m. Just for map making process its OK. For real spatial analysis you have to think.
The performance of SRTM is superior than GDEM2 in forest environment base on our finding in Northern Borneo. In our study, we could resample GDEM2 and SRTM to higher resolution (i.e. 1m, 2m and 5m). Please check the paper for more information.
http://a-a-r-s.org/acrs/index.php/acrs/acrs-overview/proceedings-1?view=publication&task=show&id=1567
Conference Paper Accuracy assessment of global topographic data (SRTM & ASTER...
use this paper "Effect of DEM data resolution on low relief region sub-watershed boundaries delineating using of SWAT model and DEM derived from CARTOSAT-1 (IRS-P5), SRTM and ASTER"
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