Low-cost uncooled IR sensor for battlefield surveillance

Abstract

Operation Desert Storm has identified the need for improved battlefield surveillance sensors to see and assess enemy threats under all battlefield conditions, including darkness. Current imaging sensors usually employ visible light cameras, Low Light Level (L<SUP>3</SUP>), Image Intensified (I<SUP>2</SUP>), or conventional Infrared (IR) cameras to detect and observe hostile forces. However, these sensors have serious deficiencies. The visible TV camera requires well lighted areas and cannot image in darkness. The L<SUP>3</SUP> TV cameras have a difficult time operating in bright sunlight or in total darkness. Image intensifiers require some ambient light and cannot penetrate camouflage or battlefield obscurants. Conventional FLIRS are costly, require an initial cool down period, and need additional power for cooling pump or periodic gas replenishment for long-term operation. Uncooled Focal Plane Array (FPA) LWIR sensors offer advantages over other imaging sensors. Uncooled IR sensors operating from 8 to 12 microns can easily operate in bright sunlight, or total darkness. They use the naturally radiated IR scene energy to create high resolution images and are not dependent on artificial light sources. Their long wave-length of operation also provides better weather penetration. Enemy vehicles and soldiers can easily camouflage themselves in the visible, but cannot hide their thermal emissions from the IR sensor.