无线激光链路超宽视场快速捕获技术研究

项目名称： 无线激光链路超宽视场快速捕获技术研究

项目编号： No.60807025

项目类型： 青年科学基金项目

立项/批准年度： 2009

项目学科： 金属学与金属工艺

项目作者： 刘璐

作者单位： 北京大学

项目金额： 21万元

中文摘要： 快速准确地捕获是无线光链路建立的前提。随着无线光通信技术的发展，许多瞄准不确定角较大的平台希望采用无线光通信技术进行大容量数传。这就给激光链路捕获技术提出了新要求。本项研究探讨无线光链路超宽视场快速捕获技术。首次提出结合鱼眼镜头和佛克脱型反常色散原子滤光器（VADOF）的超宽视场快速捕获方案。充分利用VADOF的超窄带特性和鱼眼镜头的超宽视场接收特性，使得捕获装置能在强烈的背景辐射噪声条件下，仍维持较高的接收信噪比，保证宽视场接收能力，大大减少了捕获时间。这也是VADOF首次在无线光链路中的应用。为了抑制鱼眼镜头的成像畸变，提出基于网格划分的二维双三次多项式分区间插值成像畸变抑制算法。与基于全区间的最小二乘法拟合算法相比，新算法成像畸变抑制残差小两个数量级；在保证畸变抑制精度的前提下，新算法可降低拟合多项式的阶次，具有性能优良和运算简单等特点，能满足对大倾角入射光束的快速高精度检测的要求。

中文关键词： 超宽视场捕获；原子滤光器；鱼眼镜头；成像畸变

英文摘要： Fast acquisition with high accuracy is the premise of the establishment of Optical Wireless Link. With the development of Optical Wireless Communication (OWC), many platforms with large pointing uncertainty angle hope to use OWC technology for high-capacity data transmission, which gives new requirements to laser acquisition. In this project, we first present a novel fast acquisition scheme combined with a fisheye lens and a Voigt anomalous dispersion optical filter (VADOF), which can maintain high Signal-to-Noise Rate(SNR) for the receiver while ensuring the capability of UltraWide Field-of-View receiving, and reduce the acquisition time dramatically under the condition of strong background radiation noise on the basis of the UltraWide Field-of-View of fisheye lens and the Ultra-Narrow bandwidth of VADOF. It is also the first time that VADOF is applied into the Optical Wireless Link. To mitigate the optical distortions induced by the fisheye lens, an effective distortion correcting algorithm based on 2-ary piecewise bicubic spline interpolation is presented. Compared to the least-squares method for the whole image region, the novel one can suppress the image distortion by two orders of magnitude. The novel method can reduce the order of polynomial and meet the requirement of fast detection with high accuracy for the incoming laser beam with large incident angle while guaranteeing the accuracy of image ditortion suppression.

英文关键词： UltraWide Field-of-view Acquisition;Atomic Optical Filter;Fisheye Lens;Image Distortion