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Not Georeferenced. Historic aerial photographs of Pennsylvania. |
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Not Georeferenced. Historic aerial photographs of Pennsylvania. |
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5000 |
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<DIV STYLE="text-align:Left;"><DIV><DIV><P><SPAN>This collection of historic aerial photographs was captured between April 13th, 1992 and December 9th, 1992 on various dates. The 331 photos cover areas of Allegheny and Washington counties in Pennsylvania. The photos are at a scale of 1”=1,200’ with a focal length of 152.81mm. These photos were taken by Michael Baker Jr., Inc., for the Pennsylvania Turnpike Commission. This collection was given to the Donald W. Hamer Center for Maps and Geospatial Information by the PA Department of Conservation and Natural Resources, Bureau of Geological Survey Library. The photos were scanned at 800 dpi on an Epson Expression 11000 scanner by the Donald W. Hamer Center for Maps and Geospatial Information. Approximate historic aerial photo center points were generated by staff of the Donald W. Hamer Center for Maps and Geospatial Information (https://libraries.psu.edu/maps). Photos were aligned and georeferenced in three dimensions using Agisoft Metashape using a minimum number of ground control points, typically between 5 and 12 depending on the size of the project. Estimates of each camera pose, including geographic coordinates, were then exported as a center point index to the historic aerial photography collection. This center point index is intended to facilitate discovery and access, but not for research purposes. Where photography collections facilitated the generation of high-quality seamless mosaics, these were produced to common research standards and made available along with center point indexes. Please use orthomosaics for measurement, comparison with imagery of other time-periods and other common tasks performed in a geographic information system (GIS). For more information on the methods used to generate center point indexes, orthomosaics, and/or to cite this work please see the below reference: Nathan B. Piekielek, Grace Brittany Waltemate and Karen Schuckman (2022) Evaluating Software Tools to Orthorectify Archival Aerial Photographs, Journal of Map and Geography Libraries, 18:3, 209-229, DOI: 10.1080/15420353.2023.2219257. </SPAN><SPAN>Historic aerial photograph tile indexes were generated by staff of the Donald W. Hamer Center for Maps and Geospatial Information in ESRI ArcGIS Pro. Each tile Index is based on the collection’s center point index. Photo tile size and rotation were estimated using sample georeferenced photos.</SPAN></P></DIV></DIV></DIV> |
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<DIV STYLE="text-align:Left;"><DIV><DIV><P><SPAN>The User shall save the Commonwealth harmless from any suits, claims or actions arising out of the use of the data files or accompanying documentation, or arising out of any defect in the data files or accompanying documentation. The Commonwealth excludes any and all implied warranties and makes no warranty or representation with respect to the data files or accompanying documentation, including quality, performance, merchantability, and fitness for a particular purpose. These data files and documentation are provided AS IS and the User assumes the entire risk as to their quality and performance. Those parties involved with the development and distribution of this data will not be liable for any direct, indirect, special, incidental, or consequential damages arising out of the use or inability to use the FILES or any accompanying documentation.</SPAN></P></DIV></DIV></DIV> |
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| title:
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Aerial Photographs of South Beltway, Pennsylvania 1992 |
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["imageryBaseMapsEarthCover","digital image map","aerial photograph"] |
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en-US |
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150000000 |
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