High-Resolution Measurement Method Based on Array FOV and Coded Apertures

Abstract

It is difficult to realize large field of view (FOV) and high-resolution at the same time. How to achieve high-resolution measurement under the premise of large FOV imaging is an important research issue. Aiming at the problem of single point target recognition, especially the angle measurement of single light source, this paper proposes a high-resolution measurement method with array FOV and coded apertures. A mask is added in front of the image sensor. The coded apertures on the mask divide the large FOV into several sub fields of view (sub-FOV). Different sub-FOV are time-sharing multiplexed on the image sensor. Apertures encoded by position information are arranged on the sub-FOV. When a single light source irradiates the apertures, the diffraction spot is imaged on the image sensor. The centroid method can accurately determine the centroid of light spot to submicron scale or even nanoscale. Analyzing the coded information contained in the imaging can realize the recognition of sub-FOV, and then calculate the incident angle of light to realize the target recognition. A mask is designed to realize the method. Through experiments, this mask can achieve a large FOV of 1200×120° with an angle measurement accuracy of 0.003°(3 σ).