In my spare time I am working on interpolating algorithms for Digital Elevation Models in C++. I always obtained my elevation data set as the ESRI ASCII Raster format because it is super simple.
In the past I always obtained my Data from http://gdex.cr.usgs.gov/ which is no longer supported. It was extremely easy for me to obtain this .asc-Files on their site and now it is down. And the new recommended extractor https://lpdaacsvc.cr.usgs.gov/appeears/ seems not to provide .asc-Files. Do you have a suggestion where to obtain this data without being forced to use a third party software to convert from another format to ESRI ASCII Raster format.