The military applications of remote sensing by infrared

Remote sensing is the process of acquiring information from the environment by the use of a sensor that is not in physical contact with the object under study. The military services are experienced practitioners of this old, but newly glamorous, art. Their accomplishments in the infrared, that region lying between visible light on the one hand and microwaves on the other, are both impressive and of increasing importance. Our purpose is to provide an overview of these accomplishments. We begin with a brief treatment of the characteristics and peculiarities of the infrared portion of the spectrum and of the sensors that operate there. Early military experience with remote sensing by infrared is described and an applications matrix is developed in order to provide a perspective from which the reader can view the full panorama of military applications. Specific applications ate discussed. These include strategic systems for early warning of intercontinental ballistic missile launches, methods for the detection of atmospheric contaminants, such as poison gas, under field conditions, aids for the precision delivery of weaponry (including passive, active, and laser designator guidance techniques), and sensor systems for reconnaissance and surveillance. Wherever possible, details of sensor performance are given.