About Orthophotography |
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What is Orthophotography?Orthophotography is enhanced aerial photography. It's been adjusted so than we can measure a round surface (like the earth) on a flat surface (like a piece of paper). Using these maps, you can see everything on the ground clearly and measure it at the same time. Orthophotography lets you accurately:
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How Is Orthophotography Used?Orthophotography is part of the basemap in a geographic information system (GIS). It is used like a photograph as a visual reference. And, since it has the qualities of a map, it can be used to create other important mapping data.Mapping can be used in emergencies by fire departments, EMTs and relief workers. The police can map trends in crime, realtors can find houses for sale, and doctors can track diseases. And because everyone uses the same basemap, all the information can fit back together no matter who created it. To learn more about orthophotography and see what we're doing here in Indiana, visit the Indiana GIS Initiative website. What is Pixel Resolution?Digital orthophotography is a computerized image made up of "pixels" (these are similar to the dots on a television screen that make up the whole picture). Each pixel in an orthophoto represents an actual distance on the ground. So, 1-foot pixel resolution means each little pixel in the image covers 1 foot on the ground. As you zoom in close to an image, you start to see the pixels (like getting really close to the TV screen). The higher the resolution, the more detail you see as you zoom in closer on an image.The figures below show the differences at three resolutions as you zoom in closer on the map. 1-Meter Resolution  1-Foot Resolution  6-Inch Resolution  |
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