Awesome. Thanks Andrew.
I have now added this ap to my iPhone. I think this is going to be very useful. I had a look at your website and noted the 2 pieces of software required to export and convert my local horizon to a png for SkySafari, but I have not found any published steps. Are there any?
How do YOU use this in conjunction with SkySafari and planning your observations?
It's been a while since I did it. The instructions were actually on the Sky Safari website forums. But essentially you shoot your horizon with Observatory pro. Then there is a share icon in the custom horizon pane to e-mail it to yourself. It e-mails you a CSV file or something like that, that you then save to your computer. Then you run the script that you downloaded, and pick that file on your hard drive, it should output a PNG or JPG file that is your horizon image for Sky Safari. Using iTunes you select your phone and side load the file into Sky Safari, it should show up as a horizon in the list of horizons.
I'm trying to remember all the steps, but it's been more than a year since I did it. Hopefully that's correct. If not, you can search the Sky Safari forums, or even ask support over there, and they'll point you in the right direction. Just search custom horizon or something like that.