A list of questions that xDEM should help answer

DEMs: coregistration

• What is the best (combination of) coregistration method for DEMs?
• Can DEM errors be used to improve coregistration?

DEMs: error analysis

• How to characterize DEM errors? -> Now addressed in a published study: Hugonnet et al., (2022).
• How do pixel-wise uncertainty propagate spatially (e.g., to a volume change)? -> Now addressed in a published study: Hugonnet et al., (2022).
• In gap-filling methods of DEMs and difference of DEMs, what is the uncertainty associated with missing observations?

Glaciers: volume changes

• What is the best (combination of) methods to calculate a geodetic volume change with data voids?
• How to estimate the additional uncertainty due to interpolation of these data voids? -> Some insights in: Mannerfelt et al., (2022).
• If combining several approaches (bilinear interpolation, krigging, local/regional hypsometric method etc), what is the typical void size for which each method should be used?
• How can glacier elevation be spatiotemporally estimated from multi-temporal DEM acquisitions? -> Some insights in: Hugonnet et al., (2021) implemented in pyddem.

Snow: depth of the snowpack

• What is the best approach to align DEM in mountainous terrain to avoid systematic errors in snow depth estimates?
• How can snow depth be spatiotemporally estimated from multi-temporal DEM acquisitions?