The nominal ORI data files are digital representations of the radar response signal. ORIs consist of a georeferenced pixel for a number of ground positions at regularly spaced intervals. These ORI products represent the first reflective surface as illuminated by the radar. Accuracy statements are based on areas of moderate terrain. Diminished accuracies are to be expected in areas of extreme terrain and dense vegetation.
The ORI data for 7.5-minute by 7.5-minute units correspond to the USGS 1:24,000 scale topographic quadrangle map series for available areas in the United States and throughout the world. Each 7.5-minute by 7.5-minute ORI is based on 1.25m pixel resolution. Each 7.5-minute by 7.5-minute tile provides full coverage with overlap into adjacent tiles. Data for locations above 56 degrees North/South are licensed in 7.5-minute by 15-minute tiles.
The original ORI is unenhanced and may appear dark when viewed. An ORI with a customized linear stretch enhancement is provided. The stretched ORI will appear brighter and is easy to view without additional enhancements.