dì miàn kòng zhì
ground control (of airborne or space operation)
Dì miàn Líng diǎn
Ground Zero (refers to the site of the World Trade Center destroyed in 9-11-2001 attack)
dì miàn hé bào zhà
surface nuclear explosion
zhàn dì miàn ji
floor area
occupied area
footprint (of a building, piece of equipment etc)