Gaps between tiles of OS Terrain 50 and Terrain 5 DTM data Digimap Community Q & A › Category: Data Download › Gaps between tiles of OS Terrain 50 and Terrain 5 DTM data 0 Vote Up Vote Down Anonymous asked 6 years ago Why are there small gaps between some of the adjacent tiles of OS Terrain 50 and OS Terrain 5 DTM data? The edges of the tiles should all match up perfectly.