The power of polarization is a property of light that offers more information than the traditional intensity sensing. By measuring one or more parameters of polarization, details can be extracted from a scene that is not readily apparent when using conventional thermal or visible imagers. The polarization signature of man-made objects and certain natural substances are different than the surrounding background, thus providing additional contrast in polarization imagery when compared to standard thermal or visible imagery. For this reason, objects which blend into the background when using standard thermal or visible cameras often stand out in polarization.
For more than 15 years, Polaris Sensor Technologies, Inc. has been the industry‘s leading designer and developer of polarization-based imaging systems providing daylight detail in the dark as well as visibility in low contrast conditions for military and scientific entities. These systems have provided vast improvements in mission-critical target detection and surveillance for the military warfighter. Commercial applications for these systems include, but are not limited to, autonomous vehicle navigation, facial recognition, and oil on water detection. Throughout its history, Polaris has developed a large variety of polarization sensors to meet a wide range of applications, including laboratory and field research to vehicle-mounted sensing for commercial and defense uses.
Polarization results from the vector nature of light. Fundamental quantity along with intensity and wavelength.
- IR polarization signals result from preferential emission and reflection of polarized light
- Depends strongly on the angle of incidence and surface properties such as roughness, emissivity, and reflectivity.
- The greater the angle of incidence, the greater the polarization
- The rougher the surface, the smaller the polarization signal
What is special about polarization?
Generally, manmade objects produce strong polarization signals relative to natural materials.
Other general facts about polarization:
- Polarized signal does not depend on temperature difference
- Polarized signal shows contrast between adjacent surfaces, which makes finding different surface normals and different materials easier than conventional IR and visible imagery
- Polarization enhances edges due to the abrupt change in surface orientations making it easier to find edges within an object and to find the edges of an object in a background than conventional IR and visible imagery
- Signal may be present even when unresolved