Georectified Mosaic of Aerial Images of Baltimore City in 1953

Landscape analyses are typically done using spatially explicit color aerial imagery. However, working with non-spatial black and white historical aerial photographs presents several challenges that require a combination of techniques and approaches. We analyzed 113 aerial images covering approx. 700 km2 (270 mi2) including all of Baltimore City, and a portion of Baltimore County surrounding the City. The images were taken between August 23rd 1952 and February 14th 1953. High-resolution scans were georeferenced and georectified against modern satellite imagery of the area and then combined to create a single raster mosaic. This process converted the images from a disparate set of photographs into a spatially explicit GIS data set that can be used to observe changes in land patches over time—and ultimately integrated with other long-term social, economic, and ecological data.

景观分析通常采用空间显式彩色航空影像开展。然而，处理非空间黑白历史航空影像存在诸多挑战，需结合多种技术与方法方能应对。本次研究共分析113幅航空影像，覆盖面积约700平方千米（270平方英里），研究范围涵盖完整的巴尔的摩市及其周边的巴尔的摩县部分区域。这批影像拍摄于1952年8月23日至1953年2月14日期间。研究人员先以该区域现代卫星影像为基准，对高分辨率扫描影像开展地理配准与几何校正，随后将其拼接为单幅栅格镶嵌图。该流程将原本零散的影像集转换为空间显式地理信息系统（GIS）数据集，可用于追踪随时间推移的土地斑块变化，最终还可与其他长期社会、经济及生态数据实现整合。