Which tracking method typically requires external lighting conditions?

The correct answer is the electro-optical tracking method, which requires external lighting conditions to function effectively. This method relies on visible light to detect and track objects. As it utilizes cameras and optical systems, it needs natural or artificial light to illuminate the target so that the imaging sensors can acquire clear and usable data.

In contrast, active tracking methods generate their own light, using radar or other forms of energy to illuminate targets which allows for tracking regardless of ambient light conditions. Infrared tracking can operate in low light conditions because it detects heat signatures rather than visible light. Passive methods typically rely on existing light conditions but can often leverage infrared, which does not strictly depend on external visible light conditions. Therefore, electro-optical tracking, being reliant on visibility, distinctly stands apart as the method that is specifically impacted by lighting conditions.