Final answer:
The purpose of establishing a controlled perimeter around an incident includes preventing unauthorized access, ensuring safety, and containing the incident to prevent further damage, with drone technology being a potential tool for improved surveillance.
Step-by-step explanation:
The purpose of establishing a controlled perimeter around an incident is to prevent unauthorized access to the incident area, to ensure the safety of responders and the public, and to contain the incident and prevent further damage. Implementing such controlled zones can involve setting up multiple small protected areas or selecting one small area that is isolated, especially in terms of border security where monitoring human incursions is critical. The use of drone technology has been discussed as a means for better, 24-hour surveillance to quickly address and avoid unauthorized entry into protected or sensitive sites.