New imaging modalities for laser-based systems

Laser-based electro-optical sensors can gather spatial information (imagery) as well as a variety of other types of information. These include motion detection (including vibration), color sensing, and sensing of the effects of the illuminated object on the polarization of the incident illumination. Such systems can have several advantages over sensors that rely on reflected or emitted light. Laser-based systems can gather a full 3D image of an object on a single pulse. The sensors can gather this information in a covert manner because of the high directionality of the laser illumination. Also, a laser-based sensor can gather information with high resolution. In addition, the ability to control the illumination source, the receiver, and the optical aperture can lead to new sensing modalities. We describe various spatial and non-spatial sensing concepts and discuss hardware implementations. In particular we highlight the ability of laser-based systems to produce imagery at very low light levels. The utility of low light level imagery in 2D is discussed and the potential benefits of 3D low light level imagery is assessed. The effect of intervening obscurants on low light level systems are considered. Characteristics of systems that can implement such concepts are also described.