This orthoimagery data set includes 0.5-foot (15-centimeter) 8-bit 4-band (RGBN) digital orthoimage tiles in GeoTIFF, Mr. SID, and JPEG 2000(JP2) format. The PEMA 2018 0.5-foot Orthoimagery called for the planning, acquisition, processing, and derivative products of imagery data to be collected at a ground sample distance (GSD) of 0.5-foot (15 centimeters). Project specifications are based on the U.S. Geological Survey National Geospatial Program Base Ortho Specification, Version 1.0. The data were developed based on a horizontal projection/datum of NAD83 (2011) State Plane Pennsylvania, US Survey Feet. Orthoimagery data was delivered as 298 individual 0.5-foot (15-centimeter) 1" = 100' GeoTIFF (uncompressed) 10,000-foot x 10,000-foot (3,048-meter x 3,048-meter) tiles. Aerial photography was captured during the spring of 2018, while no snow was on the ground and rivers were at or below normal levels. In order to post process the imagery data to meet task order specifications and meet horizontal accuracy guidelines, Quantum Spatial, Inc. utilized a total of 496 QC points throughout the Commonwealth of Pennsylvania to assess the horizontal accuracy of the data. These checkpoints were not used to calibrate or post process the data.
Montgomery County provides this data as a free and open resource.While every reasonable effort is made to ensure the accuracy and completeness of the data, Montgomery County makes no representations about the suitability of this data for any purpose. All data is provided "as is" without warranties of any kind, either express or implied, and it should not be construed or used as a legal description.