中文摘要：

增强现实（AR）技术是在虚拟现实技术的基础上发展起来的新兴研究领域，是一种利用计算机产生的附加信息对真实世界的景象增强的技术。AR系统的用户可以在看到真实环境的同时看到计算机产生的与之融合的文字、图片或虚拟物体的三维模型。阐述了AR系统的基本组成和关键技术，介绍了用于圆明园现场数字重建的3种增强现实系统，即定点观察式、手持个人数据助理（PDA）式和基于头盔显示器（HMD）的可穿戴式增强现实系统。阐述了各系统的结构和原理，详细说明了定点观察式系统的研制现状及初步实验结果。

英文摘要：

Augmented Reality （AR） is a new research field derived from virtual reality. It is a technology that enables computer-generated information to be superimposed on the real world. Users of an AR system can observe the real scene augmented with computer-generated text, graphics or 3D models of virtual objects. The basic constitution and key technologies of an AR system are discussed. Three types of AR systems proposed for the on-site digital reconstruction of Yuanmingyuan are introduced, including a fixed-position viewing system, a handheld personal digital assistant （PDA） system and a wearable system using a head-mounted display （HMD）. Their architectures and working principles are presented. The development status quo and initial experiment results are provided in detail for the fixed-position viewing system.