Solar Eclipse 2

彼らは次の日食を見ることができます/場合は日食のファンが知ることができます。

There will be an total solar eclipse on August 21, 2017 visible across the United States. This app will help you determine if you will be able to see it or another upcoming solar eclipse. It tells you when upcoming eclipses will occur, and how visible it will be from your location. It will also show you how visible it is from other locations, and help you find where it will be on the sky from where you are standing.

When you first start the program, it should show you a screen with your location, the date of the next Solar eclipse, and your time zone. If the program hasn't been able to find these for some reason, you can enter them yourself. See the first screenshot. It will tell you if you cannot see the next eclipse. If this is the case, you can choose another eclipse, or change your location to somewhere from which this eclipse will be visible.

At this point, from the menu or buttons, you can choose from 'Map', 'Camera', 'Glasses', 'Weather', my website, or 'Help'.

If you choose 'Map', you will be taken to a Google map showing your location and lines marking places where the Sun will be completely eclipsed, 90% eclipsed, 80% eclipsed, etc. See the second screenshot.

If you choose 'Target', you will be taken to a preview from your camera. This is basically a glorified compass, since it's sometimes hard to tell where an eclipse will show up, even if you know the coordinates. In the center of the screen is an arrow intended to guide to the location of the Solar eclipse. When the camera is facing the eclipse, the arrow disappears and a couple of circles representing the eclipse will show up. See the third screenshot.

This is an overhaul of my first (pretty old) 'Solar Eclipse' app -- https://play.google.com/store/apps/details?id=fr.free.kmganga.SolarEclipse. It includes bug fixes/improvements suggested by Brian, Michael, and Giuseppe (though these were a long time ago, so they may not even remember themselves!). I'm hoping to keep this program up-to-date, so please do (politely :-) report problems and suggest improvements.

There are still some rough edges in the program, including:

* I can't seem to systematically find the field-of-view of all cameras. If this is the case, I just assume that your field of view is the same as for my camera. This will, of course, cause (hopefully small) errors in the location of the eclipse events. Again, let this be a warning that you shouldn't use this app for precision work!

* Certainly others...

The Besellian elements used come from NASA's Solar Eclipse website by Fred Espenak.