The DRDO established a Terrain Evaluation Cell (TEC) in the Ministry of Defence in February 1964. The TEC was tasked with the "development of techniques for terrain evaluation, and assessment of mobility potential of inaccessible areas." In 1981, TEC was formally expanded into a full-fledged laboratory and renamed as the Defence Terrain Research Laboratory (DTRL).

The DTRL assesses "terrain characteristics through modern techniques of terrain evaluation," develops "infrastructure...and instrumentation in the latest techniques of terrain evaluation," and develops "terrain information databases." Other activities of the laboratory include the "preparation of mobility maps," and generation of "land-use maps" for India's Ministry of Defence and its agencies.

Sources:
[1] "Defence Terrain Research Laboratory," Defence Research & Development Laboratory, www.drdo.org;
[2] "Address Book," Defence Research & Development Laboratory, www.drdo.org.