Taking sunrise/sunset pictures at the ocean allows for photographs where the sun is placed just above the horizontal plane. This allows for "red ball of fire" pictures, such as the following by Johannes Plenio:
When in the mountains, the terrain often obstructs the horizon so that the sun, for instance, becomes visible later in the morning. By moving the viewpoint relative to the terrain, the line of sight may become unobstructed at an earlier or later time.
Since scouting and researching landscape compositions is difficult when you are unfamiliar with the local region, a software tool that helps determine what terrain features influence line of sight to the sun or moon would be a great help to me.
Is there such an app, website, or other software that takes locations within a certain area, elevation data from Google's terrain map, along with the sun's position for a given morning or evening to show where the sun will rise or set?
I am asking because I have yet to find a resource for this despite having purchased a few photography 'helper' apps such as SunSurveyor. Although the app allows me to approximate the time of appearance for a single location, it doesn't provide a way to show when sunlight is expected to appear or disappear over a wide area.