I need to perform hydrological analyses and map design purposes (hillshade creation) on a region far north. It is too northern to be covered by the SRTM DEM, therefore I am using the ASTER DEM. However, in some mountainous parts, there are missing pixels, typically occuring in the space of peaks or on the other hand in monotone environments.
The GTOPO30 DEM however, is without missing pixels, even though at a comparatively coarse resolution.
What is the best workaround to resolve the problem of missing pixels? Interpolating between the edges of the ASTER, or perhaps filling these parts with a resampled GTOPO30?
(A partly similiar sounding question was asked here, but without a resolution to the announced problem of the above question.)