Invention:
This invention provides a method to image though a disruptive media, such as fog, rain, snow, and sand particles. The phase-based camera, coupled with existing cameras and sensors normally equipped on autonomous vehicles, allows for detection and viewing objects through fog, smoke, or other atmospheric obstructions. The system consists of a lens, phase light modulation (PLM) device, 2-dimension detector array such as complementary metal-oxide semiconductor (CMOS) imager and a light source, such as a collimated laser, which illuminates the object. Return signal from an object—for example, a car in fog—is captured by camera with a PLM which is situated in the optical path between the camera lens and 2-dimentional detector array. In the system, two or more images are captured by camera while displaying phase and/or amplitude profiles which are orthogonal with each other. The images are subtracted to eliminate background and deconvolved to enhance the feature inside the fog or other disruptive media.
Background:
Camera-based object recognition and autonomous driving based on the information is one of the critical functions for Advanced Driver Assistant System (ADAS) for automotives. Camera-based ADAS is not only applicable for ground-based mobility, but also for mobility in air. Recently, Amazon announced “Amazon Prime Air,” which are FAA-approved delivery drones that carry packages while the drones are autonomously navigated by camera. All such mobility infrastructures rely upon situational awareness by camera, and other means such as radar and LIDAR. One of the common challenges in situation awareness for urban mobility as an infrastructure is robustness to inclement weather conditions, such as fog, rain, and snow. The camera-based situation awareness does not work well in such conditions. In contrast, the radar can see through fog since the wavelength is much longer compared to the length scale of fog and rainwater particles. However, known challenges include resolution and signal contrast. This technology offers radar-like capability with the resolution of an optical camera.
Applications:
Advantages:
- Reliable in inclement weather
- Improves safety
- Compact system
