Features that would be straight in a planimetric map, such as roads, power lines, edges of buildings, and edges of lots, should also appear straight in an orthorectified image. If they do not, then you may have errors in your digital elevation model (DEM) or math model solution. Re-verify the DEM and the math model solution.
If the file for the orthorectified image is too large or too small, it may indicate that:
- The DEM area does not cover the image area
- The DEM is not in the same projection as the image
- The Background Value of the DEM is incorrect
- The math model's elevation values are incorrect
- The focal length of camera is incorrect
If the orthorectified image appears smeared, it could indicate that:
- The DEM is misaligned with the math model of the image
- The DEM does not have a sufficient resolution to orthorectify the image. For example, cliffs and buildings can appear smeared if the DEM is too coarse to precisely represent the edge of the cliff or the building.
If overlapping orthorectified images do not align, it could indicate that:
- The math model contains errors, which means that you need to edit the model or add more GCPs and tie points.
- The DEM contains errors or contains insufficient detail to correctly orthorectify the images.
If OrthoEngine does not generate the orthorectified image:
- The image to be processed is not accessible (offline).
- The image is not from the demo data sets, and you are working in demo mode (unlicensed)
- The DEM file is not accessible (offline)
- The file name of the orthorectified image is missing
- The math model is not computed
- The orthorectified image already exists, but its georeferencing or resolution is incorrect.