Free Global or Quasi_Global DEMs

Free Global DEM Spacing Primary Source Producer Vertical Datum Precision Grid storage
Acquired Characteristics
SRTM (v3) 1", 3" C band radar NASA Orthometric
Integer Point Constant 2000 (11 days) Does not cover high latitudes.  Several editions, some of which may be PixelIsArea.  Instantaneous snapshot of topography
ASTER GDEM (v3) 1" Stereo NIR imagery NASA / METI Orthometric
Integer Point Constant 2000-2013 Coverage extends closer to the poles than SRTM.
ALOS World 3D
AW3D30 v3.2
1" Stereo pan imagery JAXA Orthometric
Integer Area Variable 2006-2011  
NASDADEM 1" Reprocessed C band radar NASA Orthometric
Integer or floating point Point Constant 2000 (11 days) Two beta versions, with and without hole filling.  Complete reprocessing of SRTM.   Final version in HGT format
Copernicus DEM
GLO30 and GLO90
1", 3" X band radar,
Edited commercial WorldDEM
ESA/Airbus Orthometric
Floating point Point Variable 2010-2015  
Tandem_X 3" X band radar DLR Ellipsoidal
Floating point Point Variable 2010-2015 Derived from much higer resolution data which is only available commercially or by application for research. 
MERIT 3" Radar + Stereo pan imagery Univ. Tokyo Orthometric
Floating point Area Constant 2000-2013 Combines ASTER and SRTM.  5 degree tiles.


  1. All are WGS84 horizontal datum
  2. All use the default TIFF orientation (code 274=1), with the first points in the file in the NW corner.  The DTED format starts with the SW corner.
  3. All name tiles for the SE corner (USGS NED/3DEP names for the NW corner)
  4. Except for the HGT formats for SRTM and NASADEM, in MICRODEM all will need GDAL because of particular choices in the Geotiff format.


Other 1" DEMs you might consider:


Directions for several of these DEMs from Open Topography


Free Global DEM Journal or conference paper.  "Best" is top of the list Data set home page or product description Download location Metadata files Notes
SRTM (v3) Farr, T.G., Rosen, P.A., Caro, E., Crippen, R., Duren, R., Hensley, S., Kobrick, M., Paller, M., Rodriguez, E., Roth, L., Seal, D., Shaffer, S., Shimada, J., Umland, J., Werner, M., Oskin, M., Burbank, D., and Alsdorf, D. (2007). The Shuttle Radar Topography Mission. Reviews of Geophysics 45. None

Do we want to link to OpenTopography, given that I think  they do resampling?
ASTER GDEM (v3) Abrams, M., Crippen, R., Fujisada, H. ASTER Global Digital Elevation Model (GDEM) and ASTER Global Water Body Dataset (ASTWBD). Remote Sens. 2020, 12, 1156; doi:10.3390/rs12071156

Abrams, M., Bailey, B., Tsu, H., and Hato, M. (2010). The ASTER Global DEM. Photogrammetric Engineering and Remote Sensing 76, 344-348.

T. Tachikawa, M. Hato, M. Kaku and A. Iwasaki, "Characteristics of ASTER GDEM version 2," 2011 IEEE International Geoscience and Remote Sensing Symposium, 2011, pp. 3657-3660, doi: 10.1109/IGARSS.2011.6050017. .num grid with number of scenes used, and the source of fill data  
ALOS World 3D AW3D30 v 3.2 Tadono, T., Nagai, H., Ishida, H., Oda, F., Naito, S., Minakawa, K., and Iwamoto, H. (2016). Generation of the 30 M-Mesh Global Digital Surface Model by ALOS PRISM. ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLI-B4, 157-162. doi: 10.5194/isprsarchives-XLI-B4-157-2016

Tadono, T., Takaku,J., Tsutsui, K., F. Oda, and Nagai, N., 2015. "Status of ALOS World 3D (AW3D) global DSM generation. Proceeding 2015 IEEE International Geoscience and Remote Sensing Symposium (IGARSS), 3822-3825, doi:10.1109/IGARSS.2015.7326657

Tadono, T., Ishida, H., Oda, F., Naito, S., Minakawa, K., Iwamoto, H., 2014. Precise global DEM generation by ALOS PRISM. ISPRS Ann. Photogramm., Remote Sens. Spat. Inf. Sci. II-4, 71–76.

Takaku, J., Tadono, T., Tsutsui, K., 2014. Generation of high resolution global DSM from ALOS PRISM. ISPRS — Int. Arch. Photogramm. Remote. Sens. Spat. Inf. Sci. XL-4, 243–248. .msk: mask for cloud, snow, sea, and indicates source if fill data

.stk--number of DSM scenes used
Crippen, R., Buckley, S., Agram, P., Belz, E., Gurrola, E., Hensley, S., Kobrick, M., Lavalle, M., Martin, J., Neumann, M., Nguyen, Q., Rosen, P., Shimada, J., Simard, M., and Tung, W. (2016). NASADEM Global Elevation Model: Methods and Progress. Int. Arch. Photogramm. Remote Sens. Spatial Inf. Sci. XLI-B4, 125-128. doi: 10.5194/isprs-archives-XLI-B4-125-2016

.num Source grid


Copernicus DEM GLO30, GLO90 Strobl, P. (2020). The new Copernicus digital elevation model. GSICS Quarterly, 14, 1, 17–18.  

4 auxilliary grids

Do we want to link to OpenTopography, given that they do resampling?
Tandem_X Rizzoli, P., Martone, M., Gonzalez, C., Wecklich, C., Borla Tridon, D., Brautigam, B., Bachmann, M., Schulze, D., Fritz, T., Huber, M., Wessel, B., Krieger, G., Zink, M., and Moreira, A., 2017. "Generation and performance assessment of the global TanDEM-X digital elevation model". ISPRS Journal of Photogrammetry and Remote Sensing, Vol 132, pp. 119-139.

Zink, M., Bachmann, M., Brautigam, B., Fritz, T., Hajnsek, I., Moreira, A., Wessel, B., and Krieger, G. (2014). TanDEM-X: The New Global DEM Takes Shape. Geoscience and Remote Sensing Magazine, IEEE 2, 8-23. doi: 10.1109/MGRS.2014.2318895 Substantial  
MERIT Yamazaki, D., D. Ikeshima, R. Tawatari, T. Yamaguchi, F. O'Loughlin, J. C. Neal, C. C. Sampson, S. Kanae, and P. D. Bates, 2017. "A high-accuracy map of global terrain elevations". Geophys. Res. Lett., 44, 5844-5853, None (?)  


OpenTopography (Directions) now has:

Higher resolution commercial alternatives.


Last revision 3/3/2022