I've got a worldwide SRTM grid in WGS84 and want to reproject it to UTM coordinates.
If I do so in parts of the world are strange tiles of the map (especially in Eurasia), which are not part of the UTM stripe. You see a example in the map below for the UTM 5N in a Mercator projected map. What are reasons for that? As resamping technique I used bilinear.