Layer: Orthomosaic_Cambria_County

Name: Orthomosaic_Cambria_County_2001.tif

Display Field: Value

Type: Raster Layer

Geometry Type: null

Description: Historic aerial photography seamless mosaics were generated by staff of the Donald W. Hamer Center for Maps and Geospatial Information (https://libraries.psu.edu/maps) using a structure-from-motion photogrammetry workflow as implemented in either Agisoft Metashape Professional or ESRI ArcGIS Pro’s Orthoimagery toolbar with a goal to produce a mosaic of at least 10-meter horizontal positional accuracy that was free of seamline errors and other common image distortions. For collections that were originally flown with calibrated metric cameras with known camera calibration information, this was used in the interior orientation or alignment step of the photogrammetry workflow and as an initial estimate for self-calibrated camera parameters. Where camera calibration information was unknown or never existed (non-metric cameras), camera parameters were estimated by the software with an approximate focal length starting estimate of 152mm. To achieve the horizontal positional accuracy goal, three-dimensional ground control points of high accuracy were added to the project until the root mean squared alignment error as checked by 30-40 independent test points measured less than 10-meters as described by ASPRS Positional Accuracy Standards for Digital Geospatial Data 2024. If the user’s project requires a specific horizontal or vertical positional accuracy, we encourage you to perform an independent accuracy assessment of the orthomosaics and/or contact us about producing an orthomosaic of higher positional accuracy. Also note that horizontal positional accuracy will always decrease near the edges of an orthomosaic. We chose to include edge areas of orthomosaics rather than crop them because the image edges may contain important information for a given project. Note that the original images will cover a somewhat larger area than the orthomosaics as a result of the photogrammetry workflow. For more information on the methods used to generate 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 These historic aerial photographs were taken by L. Robert Kimball, Consulting Engineers, Ebensburg, Pennsylvania at a scale of 1”=2000’. There are 403 photos in this mission, and they were taken on April 25th and 26th, 2001. This mission is part of the Cambria County PA 2001 Aerial Photos collection. The collection was given to the Donald W. Hamer Center for Maps and Geospatial Information in 2017. The photos were scanned at 800 dpi on an Epson Expression 11000 scanner by the Donald W. Hamer Center for Maps and Geospatial Information.

Copyright Text:

Default Visibility: true

MaxRecordCount: 0

MaxSelectionCount: 0

Supported Query Formats: JSON, geoJSON, PBF

Min Scale: 0.0

Max Scale: 0.0

Supports Advanced Queries: false

Supports Statistics: false

Has Labels: false

Can Modify Layer: false

Can Scale Symbols: false

Use Standardized Queries: true

Supports Datum Transformation: true

Extent:

Drawing Info:

N/A Advanced Query Capabilities:

HasZ: false

HasM: false

Has Attachments: false

HTML Popup Type: esriServerHTMLPopupTypeNone

Type ID Field: null

Fields:

OID ( type: esriFieldTypeOID, alias: OID )
Value ( type: esriFieldTypeInteger, alias: Value )
Count ( type: esriFieldTypeDouble, alias: Count )

Supported Operations: Query Query Attachments Query Analytic Generate Renderer Return Updates

Iteminfo Thumbnail Metadata

Layer: Orthomosaic_Cambria_County_2001.tif (ID: 0)