1. Image Capture, Correction, Orthorectification, and Photogrammetry
PTYS Lecture 4
Eyjafjallajökull, Iceland

17. Scale

18. Scale

19. Scale

20. Orientation

21. Parallax

22. Triangulation

23. Summary
There is no such thing as a standard camera. Every camera design involves a series of trade-offs that are balanced to address a particular problem.
Images include many forms of distortion that must be corrected for to use the data in a quantitative fashion. Examples include photogrammetric correction, geometric correction, and othorectification.
Shadow measurements can help to provide inforation about the relief of features within a scene, but are prone to many sources of error due to the unknown orientation of objects and ground slopes within a scene, as well as diffuse shadows and albedo variations within the target material
Light Detection And Ranging (LiDAR) provides absolute control on the elevation of surfaces (defined relative to a datum), but laser shot spacing may be large, thereby requiring signifignt interpolation between highly accurate and precise spot measurements.
Photogrammetry and LiDAR are complementary, with high resolution stereo-images enabling vastly improved spatial resolution, but benefiting from ranging data (or ground control points) to ensure that the relative elevations calculated through photogrammetry are tied to a datum.