无人机载超低空宽覆盖遥感相机光学系统设计

Design of Optical System for UAV-Borne Ultralow-Altitude Wide-Coverage Remote Sensing Camera

基于对称前置同心物镜和中继转像透镜阵列设计的新型级联光学成像系统,是同时实现宽覆盖和高分辨率航拍作业的有效途径。针对超低空精准农情监测和精准施药需求,通过研究新型级联光学成像系统在超低空飞行高度下获取的最佳中间曲面像面面型及位置,研究并设计适用于超低空飞行高度的新型级联光学成像系统。在设计时,针对无人机(UAV)轻小型载荷需求,在系统中通过引入非球面来平衡轴外像差、减少镜片数量、缩短光学系统筒长。基于此,优化设计了飞行高度为20~80 m、焦距为60 mm、F数为3.4的无人机载宽覆盖遥感相机光学系统,其视场角高达132°,实现了地面宽覆盖,且成像性能优,为农用无人机精准高效农情监测提供了重要参考途径。

The novel cascaded optical imaging system designed herein is based on a fore monocentric symmetric objective and a relay lens array, enabling wide-coverage high-resolution aerial imaging. To satisfy ultralow-altitude requirements for precision agriculture monitoring and pesticide application, we propose a cascaded optical imaging system for ultralow-altitude flight focusing on the optimal mid-curved surface shape and location. Considering the light and small load capabilities of unmanned aerial vehicles(UAV), an aspheric surface is integrated into the system to balance the off-axis aberration, reduce the number of required lenses, and shorten the tube length. The designed optical system comprising a UAV-borne ultralow-altitude wide-coverage camera adopting the proposed cascaded optical structure requires a low altitude of 20--80 m, a focal length of 60 mm, an F-number of 3.4, and a field-of-view of 132°. As expected, the proposed system provides a wide ground coverage and excellent imaging performance under ultralow-altitude flight, thus demonstrating its potential for accurate and efficient agricultural situation monitoring of agricultural UAV.