In recent years software has replaced hardware in computer networks. Smarter algorithms allow for more robust processing without the need for bigger, more elaborate machines. A similar evolution has been taking place the arena of military detection known as spectral sensing.
Spectral sensing (also called hyperspectral) uses reflected light to determine the material properties of an object. It’s been used for decades in aerial implementations as a means to detect troops and weaponry. Recent evolutions have made spectral sensing a viable tool for ground troops.