I have a question for you . As I am working on using ERDAS Autosync to orthorectify from an ungeoreferenced aerial photos to known reference image. I have a DEM that to go with it as well.
I understand that in order to use “Tie” points or control points need to have them to be spread out. What I would like to see is an example of control points? I have been in searching for this information on google and I find very limited on it. What I would like to find the information that I prefer to see them in pictures or they can come from the research papers to show what control points looks like. It will help me to understand how spread-out they need to be.
Here is the example I found :
http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.516.2917&rep=rep1&type=pdf