Airborne or ship-borne gravity meters (with an accuracy of 1 mgal or higher, steady-state recording time ≤2 minutes) 机载或舰载重力仪(精度为1毫伽或更好、稳态记录时间至多为2分钟的),
Airborne or ship-borne gravity gradiometers (with an accuracy of 1 mgal or higher, steady-state recording time ≤2 minutes) 机载或舰载重力梯度仪(精度为1毫伽或更好、稳态记录时间至多为2分钟的),