spotter [ˈspɑ:tə(r)]

例句:

• I was a devoted train spotter.
  我是个酷爱看火车的人。
  
• He's an avid train - spotter.
  他特别喜欢观察火车.
  
• The spotter planes reported splashes as hits, then corrected themselves.
  弹着观测机把溅起的水柱汇报成命中, 然后自行更正.
  
• Weather spotter, like that means anything.
  来自SA
• One man remained, talking on a cellphone, a likely spotter for insurgents.
  来自WSJ
• There were planes flying out for logistics, spotter planes, planes spraying dispersants.
  来自NEWYORKER