In military applications, what medium is commonly used for transmitting infrared radiation?

Infrared radiation is commonly transmitted through the atmosphere, which is essential for various military applications such as targeting systems, surveillance, and communications. The atmosphere allows infrared waves to travel relatively unimpeded over varying distances, depending on atmospheric conditions. In military scenarios, this characteristic is utilized for effective detection and tracking of objects without relying on physical mediums that might impair signal integrity.

In contrast, a vacuum does not contain air, which can hinder the propagation of other forms of electromagnetic radiation, but infrared can still travel through it. However, it is not as applicable for most military uses outside of space operations. Water can absorb infrared radiation significantly, which would degrade transmission effectiveness and limit its utility in many operational contexts. Solid materials can also attenuate infrared radiation, making them less effective for transmitting infrared signals compared to the open atmosphere. Overall, the atmosphere serves as the most advantageous medium for delivering infrared signals in military applications.