Chamoli Disaster Pre-event DEM (2015-05-07 WorldView-1 Stereo)

NOTE: The final version of this pre-event DEM, with improved coverage can be found here: https://zenodo.org/record/4554647.  Please use that open-access product, as this is a preliminary product with inferior quality.

WorldView-1 Stereo DEM from May 7, 2015

This “fine quality” 2-m DEM was generated using the NASA Ames Stereo Pipeline v2.6.2_post (Beyer et. al, 2018; build d7eb7c8) and a modified version of the methodology presented in Shean et al. (2016).  Input Maxar/DigitalGlobe WorldView-1 images were acquired on May 7, 2015 (Catalog IDs: 102001003B302F00 and 102001003CC9C100).  Images were orthorectified at the native 0.54 m GSD using the 30-m Copernicus DEM (converted to ellipsoidal heights) and cropped to the region of interest for the February 7, 2021 event.

Specific ASP correlator settings, beyond defaults (https://stereopipeline.readthedocs.io/en/latest/stereodefault.html):

--stereo-algorithm 2 (More Global Matching (MGM))

--cost-mode 3 (census transform)

--subpixel-mode 9 (SGM Poly4) 

--corr-kernel 7x7 px 

--subpixel-kernel 15x15 px

Output DEM (height above the WGS84 ellipsoid) was posted at 2.0 m with UTM 44N projection (EPSG:32644). The output DEM was then co-registered to a filtered/masked version of the 30-m Copernicus DEM, with no additional gap filling or filtering. A shaded relief map is included for visualization.  Both files are tiled, LZW-compressed GeoTiff format with internal overviews (GDAL gauss resampling, to help fill residual gaps).

An initial version of the full 8-m DEM strip for this stereo pair was released as HMA_DEM8m_AT_20150507_0635_102001003B302F00_102001003CC9C100.tif in the NSIDC HiMAT data portal: https://nsidc.org/data/HMA_DEM8m_AT/versions/1.

If you use these data products, please cite this Zenodo repository (https://doi.org/10.5281/zenodo.4533679) and the Frontiers paper:

Shean, D. E., Bhushan, S., Montesano, P., Rounce, D. R., Arendt, A., & Osmanoglu, B. (2020). A Systematic, Regional Assessment of High Mountain Asia Glacier Mass Balance. Frontiers in Earth Science, 7. https://doi.org/10.3389/feart.2019.00363.

Support provided by NASA High-Mountain Asia Team (HiMAT) and NASA Commercial Smallsat Data Acquisition Program (CSDAP). The Level-1B WorldView images were accessed under the NGA NextView license. Resources supporting this work were provided by the NASA High-End Computing (HEC) Program through the NASA Advanced Supercomputing (NAS) Division at Ames Research Center.