Keyhole Imagery Global Coverage Dataset (1960–1984)

This project provides the <i>Keyhole Imagery Global Coverage Dataset (1960–1984)</i>, a globally consistent framework for evaluating the spatio-temporal availability of declassified U.S. Keyhole reconnaissance imagery. The dataset is built on a regular 0.1° global grid of ~6.5 million points and integrates multiple resolution classes (C1: meter-level, C2: five-meter, C3: ten-meter). Standardized indicators are provided, including cover count, number of unique observation dates, first/last observation year, temporal span, maximum observation gap, peak observation year, and multi-period coverage classification.The project includes three components:<b>Download_data</b>: Including six shapefile files (<code>Declass1_free,Declass2_free,Declass3_free,</code><code>Declass1_full,Declass2_</code><code>full</code><code>,and Declass3_</code><code>full</code>) downloaded from USGS explore.<b>Code</b>: Python scripts implementing the three-step workflow (imagery classification, global grid generation, and point-based property calculation).<b>Figures</b>: Visualizations used in the article (C0 layers) and supplementary figures for C1–C3.<b>Results: </b>The results processed by Codes and download_dataThe dataset supports reproducible Earth system research, historical land use reconstruction, and environmental change studies. Users are encouraged to cite the associated publication and dataset DOI when using these resources.