NIST Imaging System Detects Hidden Threats

The video tutorial introduces a video imaging system designed for remote detection of concealed weapons. It highlights the system's ability to operate at long distances and its passive nature, which relies on detecting natural light. The system comprises 251 detectors developed at NIST, functioning like sensitive thermometers. A demonstration shows how the system captures thermal images, identifying warmer and cooler areas, and successfully detects a concealed ceramic knife.

Describe how the system detects objects.

What does the color representation in the video image indicate?