What type of reconnaissance is typically followed after Phase 1?

The type of reconnaissance that typically follows Phase 1 is detailed or focused reconnaissance. This stage builds upon the preliminary findings and insights gained from Phase 1, where initial observations and assessments are made. During detailed or focused reconnaissance, the effort shifts to gathering more specific, in-depth information about a target area or subject. This includes refining initial hypotheses and moving towards a deeper analysis based on the information collected during Phase 1.

This phase emphasizes the collection of detailed data that may involve site visits, engaging with sources, and utilizing specialized tools or methods to extract richer insights. By doing so, analysts can optimize their understanding of the operational environment and ensure that subsequent decisions or actions are well-informed.

The other options pertain to different methodologies or types of reconnaissance but do not specifically follow the Phase 1 framework. Advanced aerial reconnaissance typically refers to the use of drones or aircraft for reconnaissance afterward, which may not directly align with the detailed, ground-based approach. Thorough open-source investigation is more about gathering information from publicly available resources rather than focused data collection based on previous findings. Lastly, statistical reconnaissance would involve quantitative analysis, which may not accurately reflect the needs for in-depth understanding immediately following the initial observational phase.