Philadelphia aerial photography 2018

Pennsylvania Spatial Data Access (PASDA) The Pennsylvania Geospatial Data Clearinghouse

Data Source

https://www.pasda.psu.edu/uci/DataSummary.aspx?dataset=2019

Description

Color Citywide digital orthophotography with a ground resolution of at various resolutions, georeferenced to the Pennsylvania State Plane Coordinate System, and delivered as individual and mosaicked raster images. The dataset consists of tiled orthogonal imagery produced from nadir images captured by various contractors during the months of April and May.

The dataset consists of tiled orthogonal imagery produced from nadir images captured by Pictometry International. Automatic aerial triangulation (AAT) was performed. The triangulated frames were rectified to a LiDAR derived DEM. Mosaicing was performed using an automatic seaming algorithm and manually edited to eliminate seams through elevated features where possible. 

Flight plans were prepared to capture image frames with 60% forward overlap and 30% sidelap in order to provide sufficient overlap for automatic aerial triangulation and mitigation of building lean in orthophotography produced. Source imagery was acquired during times of optimal environmental conditions. Imagery will generally be captured when solar altitude is 30 degrees or greater and/or by using the most optimal four-hour window, except where capture season offers significantly longer window. Imagery was acquired with ground free of snow cover and deciduous vegetation less than 30% of full bloom. Frames with clouds were rejected and reflown. Any planned deviation from these conditions imposed by capture window constraints was discussed with client prior to commencement of acquisition. 

Prior to the production of orthophotography, the vendor performed automatic aerial triangulation, utilizing the directly observed Exterior Orientations (EOs) and ground control points (GCPs), measured by a licensed surveyor, for the purpose of orienting the individual frames for creation of the final ortho imagery. In addition to the GCPs, sophisticated matching techniques was employed to automatically create tie points for use in performing a bundle adjustment. The vendor utilized best available Digital Terrain Models, combined with the calibrated camera interior orientations, ground control points, and triangulated EOs to rectify the images. When the rectification requires a resampling of the source imagery, a cubic convolution method was utilized.

Credits

Pennsylvania Spatial Data Access (PASDA)
Philadelphia Office of Innovation and Technology
Pictometry International Corp.

Access/Use Constraints

The City of Philadelphia reserves all rights in the City’s databases and any data contained therein, and the end user’s use of the data does not constitute a transfer of, nor does the end user receive, any title or interest in the database or any other City data. The City of Philadelphia makes no representation about the accuracy of any specific information in this data and is provided “as is” and without Warranty of any kind. The user of this data will assume complete responsibility for any and all occurrences resulting from its use or display and will hold the City of Philadelphia harmless from any and all claims, demands, liabilities, obligations, damages, suits, judgments or settlements, including reasonable costs and attorneys’ fees, that arise from use of this data.

Distribution Liability

This dataset contains errors that are an artifact of the interpretation, source material and conversion process. The data and documentation are provided “as is.” The City of Philadelphia (CITY) makes no warranty or representation, either express or implied, with respect to the data or accompanying documentation, including its quality, performance or accuracy. The CITY will not be liable for any direct, indirect, special, incidental, or consequential damages arising out of the use or inability to use the data or any accompanying documentation. The CITY is working to correct errors found in its datasets. Users discovering errors or making corrections to the data are requested to report such errors to the CITY at 215-686-XXXX

Map software is provided ‘as-is’, without any express or implied warranty. In no event will boydsmaps.com be held liable for any damages arising from the use of this software. The user assumes all risks associated with the use of this software. boydsmaps.com will not be held responsible for any inaccuracies and no responsibility is assumed for damages or other liabilities due to errors, installation, accuracy, availability, use or misuse of the data presented.

Full Metadata Link

https://www.pasda.psu.edu/uci/FullMetadataDisplay.aspx?file=PhiladelphiaImagery2018.xml

Downloadable Version for Offline Use

None available at this time.