What is another word for recon?

There isn't one single perfect synonym for "recon," as it depends on the context. Here are some options depending on what kind of reconnaissance is meant:

General Reconnaissance:

* Exploration

* Survey

* Investigation

* Scrutiny

* Examination

* Inspection

* Observation

* Assessment

Military Reconnaissance:

* Scouting

* Patrol

* Intelligence gathering

* Surveillance

Other:

* Research (if referring to gathering information for a project)

* Fact-finding (if referring to investigating a specific incident)

* Pre-planning (if referring to gathering information before an event)

The best word to use will depend on the specific context and the nuance you want to convey.