Because mid-wave infrared (MWIR) and long wave infrared (LWIR) technologies measure radiation inherent to the object and require no external light source, they also are referred to as thermal imaging methods. The brightness of the image produced by a thermal imager depends on the objects emissivity and temperature. Every material has an infrared signature that aids in the identification of the object.

These signatures are less pronounced in hyperspectral systems (which image in many more bands than multispectral systems) and when exposed to wind and, more dramatically, to rain. Sometimes the surface of the target may reflect infrared energy. This reflection may misconstrue the true reading of the objects’ inherent radiation. Imaging systems that use MWIR technology function better with solar reflections on the target's surface and produce more definitive images of hot objects, such as engines, compared to LWIR technology. However, LWIR operates better in hazy environments like smoke or fog because less scattering occurs in the longer wavelengths.

Researchers claim that dual-band technologies combine these advantages to provide more information from an image, particularly in the realm of target tracking. Įor nighttime target detection, thermal imaging outperformed single-band multispectral imaging. Dual band MWIR and LWIR technology resulted in better visualization during the nighttime than MWIR alone.

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