WHICH FILE TO CHOOSE?
Terrain Category 2 (TC2): Open terrain, including grassland, with well-scattered obstructions having height generally from 1.5m to 5m, with no more than two obstructions per hectare, eg. farmland and cleared subdivisions with isolated trees and uncut grass.
Terrain Category 3 (TC3): Terrain with numerous closely spaced obstruction having heights generally from 3m to 10m. The minimum density of obstruction shall be at least the equivalent of 10 house-sized obstructions per hectare. e.g. suburban housing or light industrial estates.