High resolution orthorectified images combine the image characteristics of an aerial photograph with the geometric qualities of a map. An orthoimage is a uniform-scale image where corrections have been made for feature displacement such as building tilt and for scale variations caused by terrain relief, sensor geometry, and camera tilt. A mathematical equation based on ground control points, sensor calibration information, and a digital elevation model is applied to each pixel to rectify the image to obtain the geometric qualities of a map.
A digital orthoimage may be created from several photographs mosaicked to form the final image. The source imagery may be black-and-white, natural color, or color infrared with a pixel resolution of 1-meter or finer. With orthoimagery, the resolution refers to the distance on the ground represented by each pixel.
Georeferenced orthoimages support a variety of geographic information analysis and mapping applications, and provide the foundation for most public and private Geographic Information Systems.
High Resolution Orthoimagery Products
The High Resolution Orthoimagery collection was acquired through USGS contracts, partnerships with other Federal, state, tribal, or regional agencies, and direct purchases from private industry vendors. Since data came from a variety of sources, the resolution, area of coverage, file size, and projection varies by dataset. The USGS EROS Center manages and distributes this orthoimagery, which includes black-and-white, natural color, color infrared, and color near-infrared. Digital download products are available in a Georeferenced Tagged Image File Format (GeoTIFF).
Coverage Maps
Coverage Maps indicating the availability of High Resolution Orthoimagery (HRO) products are available for download.
Access Data
EarthExplorercan be used to search, preview, and download High Resolution Orthoimagery (HRO). The collection are located under the Aerial Imagery category.
Digital Object Identifier (DOI)
High Resolution Orthoimagery (HRO)Digital Object Identifier (DOI) number: /10.5066/F73X84W6
