Correct

航测

/ háng cè / 
Strokes

Example

As a Noun

aerial/airborne survey

1
Hángcè
航测
shèyǐngjī
摄影机

aerial surveying camera

2
Hángcè
航测
píngmiàntú
平面图

aerophotographic plan

3
Hángcè
航测
fēijī
飞机

air-mapping aircraft