noun-modifying (irregular)
ground-; relative to the ground
Prenominal modifier used in technical, military, and aviation contexts to describe something relative to the ground, such as ground speed, ground attack, or ground clearance.
The ground speed reached 800 km/h.
The fighter has high ground-attack capability.
対地 describes something aimed at or relative to the ground, while 対空 describes something aimed at aircraft, so the two are easily mixed up despite the identical 対〜 pattern.
対地 targets ground or land positions, whereas 対艦 targets ships, making these two military prefixes easy to confuse.
Compound of 対 (たい, 'facing, against') and 地 (ち, 'ground, earth'). The reading たいち follows standard on'yomi.