Which of the following is NOT a CBRN surveillance technique?

• A. Periodic surveillance
• B. Continuous surveillance
• C. Area Array surveillance
• D. Geospatial mapping surveillance

Answer: (D)

In CBRN surveillance, the emphasis is on methods that actively monitor for chemical, biological, radiological, or nuclear threats using sensors or planned checks. Periodic surveillance fits because it involves checks at set intervals to detect contaminants or anomalies. Continuous surveillance fits because it relies on real-time or near real-time monitoring by sensors to catch changes as they happen. Area Array surveillance fits as well because it deploys a network of sensors across a defined area to detect signals indicating a threat. Geospatial mapping surveillance, however, is about plotting and analyzing spatial data to visualize where events are occurring or how they might spread; it supports understanding and decision-making but does not itself perform detection or ongoing monitoring of CBRN agents. Therefore, it is not considered a direct CBRN surveillance technique.