SRTM .hgt-File Import/Export: values of data voids not according to the standard

sonny

Hi!

I noticed that GM is using a non-standard value (-9999) for data voids if exporting an elevation grid to a SRTM .hgt file. This could cause problems on the import with other software which are relying on .hgt-files according to the official standard-value (-32768):

https://www2.jpl.nasa.gov/srtm/faq.html#data

On the other hand if importing .hgt-files with GM, it just recognizes the value -9999 as data void, but not the standard-value -32768 (which is treated as valid elevation value)

sonny

I think it would be also a good idea to be able to define a custom NODATA or VOID value within the Configuration. So people are able to load or export files with custom NODATA elevation values. So for example I could export or import .hgt files either with VOID values of -9999m or with -32768m.