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What do you need to know about orthorectification?
Orthorectification is the process of removing the effects of image perspective (tilt) and relief (terrain) effects for the purpose of creating a planimetrically correct image.
Which is the original image and the orthorectified image?
On the left is the original image, and on the right is the orthorectified image. In the orthorectified version, you can see that the path is now nearly straight after the influence of topography has been removed from the image. ( Graphic Credit: David DiBiase, Penn State University)
How is the accuracy of an orthoimage calculated?
The resulting accuracy of the orthoimage is based on the accuracy of the triangulation, the resolution of the source image, and the accuracy of the elevation model. OSSIM Sensor Modeling Command line application used to orthorectify images and create orthoimage mosaics.
How are orthorectified images used in Google Earth?
This allows for the accurate direct measurement of distances, angles, and areas (i.e. mensuration). Orthorectified images are commonly used as in visualization tools such as Google Earth, OSSIM Planet, ArcMap, WMS, etc. The requisite inputs for orthorectification:
How is geometric correction performed in your project?
Within the automatic workflow, geometric correction is performed with an R script that makes use of GDAL. This script performs orthorectification based on the .RPC files delivered with the images and a DEM of the user’s choice, which in the case of the STARS project is the 30m SRTM DEM product.
What are the steps in the geometric correction process?
Two fundamental steps are required in geometric correction: 1 Geo-rectification: at this stage, an appropriate map coordinate system must be defined for the image. This is normally… 2 Orthorectification: this is the process of correcting the image for image distortions caused by variations in the… More