What are the three most common sensor modes?

• A. DTV, IR, Visible
• B. DTV, IR, LWIR
• C. DTV, IR, SWIR
• D. Visible, Near IR, SWIR

Answer: (C)

The idea being tested is how imaging systems access and present data across different spectral or output formats. In practice, a sensor’s mode often means the way it captures and delivers imagery: a standard digital video output, an infrared (thermal) capture, and a spectral range that gives useful detail in challenging conditions.

Digital video is the familiar, widely compatible way sensors feed images into displays and recording systems. It ensures the data can be quickly viewed, processed, and stored without special translators. Infrared imaging reveals heat differences, so you can see people, animals, or equipment in the dark or through limited lighting, making it indispensable for night surveillance and search tasks. Shortwave infrared sits between visible light and longer-wavelength infrared, offering good material contrast and visibility through some obscurants like smoke or light fog, which aren’t as easily resolved in visible light.

Together, these three cover the most practical and frequently used modes: a standard digital video output, a thermal infrared view, and a SWIR view for clearer material discrimination under challenging conditions. The other options either drop the digital video standard or swap in a less universally relied-on infrared band, which is why they’re not as representative in this context.