OK. That's helpful and thanks for updating your profile.
So in order to prove that the shadows are a reasonable representation of reality, perhaps you could geolocate a sample model at the offices of the government agency and show the shadows for the current date at a specific time. Maybe use a flag pole on the site so they can compare the image to what they see when they go out there and look at it.
Reminds me of a project I did for a client in Maine some years ago. I'm in Minnesota and at the time I was working on the project I'd never seen the site. The city folks wanted proof the dimensions I was giving them from the site were accurate. I created a simple drawing of their municipal building (which I had also never seen in person) and told them how long and deep it was. That convinced them and my client prevailed over a contractor who was providing extremely inaccurate pencil sketches.
