How Does the Military Uses black body radiation?

The world of physics is ever expanding, and the technology is definitely keep up with it by constantly implementing the latest scientific discoveries. Many of these technologies use physics concepts like black body radiation, light photons, and thermal radiation to bring an advanced layer of accuracy and efficiency. For example, the military uses many of these discoveries to aid in their missile tracking systems.
Concept
The concept behind black body radiation is actually fairly simple. People without advanced degrees in physics should be able to understand these basic principles that this form of radiation is built upon. To build up to an explanation, the working of light should be briefly discussed. Light is a form of energy that is divided into two categories, visible and invisible. It is visible light when colors are displayed, and each color is only displayed because of the material of that particular item. For example, grass appears green because it doesn’t absorb much of the green part of the light spectrum, which means that the green light is bounced back.
However, black objects actually absorb all parts of the light spectrum. Given a few principle laws, like energy can neither be created or destroyed, it is obvious that the object has to do something with the energy it absorbs from the light. It does. It emits black body radiation. The black object gives off an aura of light that is in the invisible spectrum, meaning that the naked eye cannot see it. Although, if heated significantly enough, the object will actually begin to glow visibly, like when a black pot is heated up to ‘red hot.’ In fact, every object will do this. Human bodies give off thermal radiation under the same premises.
Military Use
The military has actually made great use of this technology. Outside of the common thermal goggles that Hollywood movies display being used to give military members a form of night vision, it can also be used to aid missile targeting systems in acquiring the correct location. The accuracy and efficiency of these devices are, as can be imagined, extremely important for a number of reasons. That is why scientists of discovered methods to calibrate and maintain machines that will, effectively, give the military a fool-proof method of marking a target that is within range.
So, how does it work? This is also quite simple. There are amazing high-powered lasers that can be pointed at a target location. These lasers will force the target’s black body radiation to go into a certain spectrum, which is a pre-determined and very specific range of the spectrum. When the missile is launched, it will have a tracking system that will look for that particular range and lock on to it. This might not sound like a great plan, but the range of light emission is extraordinarily large and can be specified nearly infinitely. While it isn’t ‘technically’ impossible for there to be a similar signature in the area, it is highly unlikely considering that certain determinations need to be met like intensity and basic geographic location.