[MP5SD]

Infrared is a spectrum of non-visible light that is generated a power source and visible with night vision devices

Thermal uses heat ONLY. No heat = no image

The next generation of Night vision goggles use a combination of of light amplification and thermal. Very clear image.

There are now IR Illumination rounds for mortars, etc. Fired into the sky and illuminate the area in IR. No NVGs = you don't see squat.

[Happy2BMe]

[Tree of Liberty]

Thanks for the clarification.

[Doomonyou]

I see, said the blind man.

Thanks.

[MP5SD]

Also you can obscure NVGs with simple smoke. Can't do that to a thermal imager, it sees through smoke....unless you got the right smoke ;) The "right" smoke has an added component that will obscure even thermal viewers.