偵察

1. Origins, structure, and basic meaning

• Structure: 偵察(ていさつ) is a noun for reconnaissance or scouting performed before a main action.
• Basic usage: It takes a scouted place with を in 谷を偵察する and marks a purpose in 偵察に向かわせる.

2. Common pitfalls and similar expressions

• Object and purpose
  • Use を for the place being scouted and 偵察に when sending someone or something out for reconnaissance.
• Noun and verb use
  • 偵察 names the activity, while 偵察する directly states the action of scouting.