Message posted by greatguess on August 23, 2011 at 19:02:51 PST:
with a new sat image inbound i would like to learn the best way to estimate heights of items on the image. i will explain how i do it but would like some inputs from other folks who share this forum on a better method. MY approach is simple but flawed; it is based on knowing the exact height of one object somewhere in the image. knowing that height i can measure the shadow and know the object height to shadow relationship for the entire image and then start getting heights of other objects based on their shadows. this of course works best when the image has a low sun angle wrt the base and the known object is relatively tall. the flaw in my approach is that i don't know the exact height of ANYTHING on the base to start the process. i have looked at janet tail shadows, water tower shadows, utility pole shadows, etc, but i don't know the exact height of any of those. so that's how i do it. i am looking for any suggestions on a more accurate method we could all employ so as we study the new sat images we can all be calculating object heights in roughly the same way? thanks for any inputs ahead of time.
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