Event-Camera-Based Optical Turbulence Compensation (3b)

Physical Sciences Inc. (PSI) will develop a sensor and software to provide real-time correction of optical- turbulence-induced distortion in video imagery and enable reduction of optical-turbulence-induced laser beam spread. The proposed sensor will enable distortion correction of video imagery at >1 kHz update rate without the use of adaptive optics or processing of multi-image sequences. The sensor may be converted to a Shack-Hartmann wavefront sensor with equal or greater response bandwidth. The proposed innovation addresses the Department of Energy’s objective to increase standoff range and minimize measurement noise in remote sensing applications by exploiting edge sensing. The objective of the Phase I project is to demonstrate that correction of optical-turbulence-induced image distortion can be accomplished faster and in a more computationally-efficient way using data from an event camera rather than processing a multi-image sequence. We believe that event cameras are ideally- suited for this application because they provide a continuous asynchronous stream of high-bandwidth (>100 kHz) of intensity change data necessary to determine the distortion correction. Data provided by event cameras is not frame-rate-limited because they do not output frames; that they only output spatially- resolved change information greatly reduces data throughput relative to a conventional video camera. The Phase I program will demonstrate that data from an event camera may be used to correct optical- turbulence-induced image distortion faster and more efficiently than can be accomplished by direct processing of video sequences. The Phase I program will be consist of data collection, algorithm development, and data analysis. We will collect imagery through a turbulent atmosphere using a commercially-available event camera which has a conventional (40 Hz) video output as well as event output. To demonstrate proof-of-principle, we will: 1) develop an algorithm to distortion-correct video using an event camera data stream, 2) distort-correct imagery using that algorithm, 3) distort-correct imagery using an establish video processing method and 4) compare the results of the two approaches. Presuming a favorable result in #4, we will develop a conceptual for a sensor to be built in Phase II. The proposed sensor will be used in conjunction with an imaging sensor or laser-based illumination system to improve the spatial resolution of imagery and to enable laser illumination systems to deliver more power on target. Applications of the proposed sensor include: Image quality enhancement of airborne surveillance imagery. Image quality enhancement of ground-level tactical, ship-board and surveillance imagery. Increase energy on target for laser designators and high-power laser weapons.