Unlocking the Past: A Review of Digital Processing of Historical Aerial and Satellite Stereo Imagery for Geoscience Applications

Dramatic changes have occurred over the past century in many parts of the planet due to natural factors and intensifying human activities. Understanding these changes is critical for quantifying long-term environmental trends and modelling future conditions. A vast, underexploited resource for such analysis lies in historical aerial and satellite stereo imagery captured with analogue cameras from the early 1900s to the early 2000s. Originally acquired for military and mapping purposes, the stereoscopic nature of historical images offers a unique potential to reconstruct 3D Earth surface changes across the 20th century. Recent advances in photogrammetry and computer vision have greatly enhanced this potential. Despite the early recognition of their value, these datasets remain underexploited due to challenges related to: fragmented and inaccessible archives, digitisation and associated costs, and a lack of scalable, automated processing solutions. This review addresses these challenges by analysing 198 studies that digitally process historical aerial and satellite stereo imagery for orthoimage and DEM generation. We provide an overview of accessed archives, processing strategies, and software pipelines. We discuss emerging tools and advanced image-matching algorithms that are improving automation and georeferencing and highlight how historical imagery can support a wide range of geoscientific applications, from climate change to urban development. Finally, we emphasise the urgent need to unlock these archives and develop efficient, reproducible workflows to preserve and exploit this irreplaceable remote sensing dataset before physical degradation or institutional neglect makes it inaccessible. Information about the dataset and analysis scripts can be found in the README file, or on the dataset webpage.过去一个世纪以来，全球诸多区域因自然因素与日益加剧的人类活动发生了剧烈变化。明晰此类变化，对于量化长期环境趋势、模拟未来环境状态至关重要。 此类分析所需的海量未充分利用资源，藏于1900年代初至2000年代初由模拟相机拍摄的历史航空与卫星立体影像（Stereo Imagery）之中。这类影像最初为军事与测绘目的采集，其立体特性为重建20世纪地球表面三维变化提供了独特潜力。近年来，摄影测量（Photogrammetry）与计算机视觉（Computer Vision）领域的进展极大提升了这一潜力的发掘空间。 尽管学界很早就认识到其价值，但由于以下相关挑战，此类数据集仍未得到充分利用： - 碎片化且难以获取的档案； - 数字化工作及相关成本； - 缺乏可扩展的自动化处理解决方案。 本综述通过分析198项针对历史航空与卫星立体影像的数字化处理研究（用于生成正射影像（Orthoimage）与数字高程模型（Digital Elevation Model，DEM）），旨在应对上述挑战。本文概述了可获取的档案资源、处理策略与软件流水线；讨论了可提升自动化与地理配准（Georeferencing）水平的新兴工具与先进影像匹配算法；并阐述了历史影像如何支持从气候变化到城市发展等广泛的地球科学应用。最后，本文强调了亟待开放此类档案资源、开发高效且可复现的工作流的必要性，以在这些不可替代的遥感（Remote Sensing）数据集因物理老化或机构忽视而彻底无法获取之前，完成其保存与开发利用。 有关该数据集与分析脚本的信息，可查阅README文件或数据集网页。