Earth, Sun and Moon (EarthView) app for iPhone and iPad
Developer: Craig Vosburgh
First release : 03 Feb 2009
App size: 1.17 Mb
This application can determine your location on the Earth (via location services or through manual entry) and calculate the Sun and Moon rise/set times for that location. You can enter the elevation you would like to use for the calculation to allow for determination of astronomical (-18deg), nautical (-12deg) and civil twilight (-6deg) as well as the physical horizon (use -.5deg for the elevation as the atmosphere acts as a lens for the apparent position of the Sun and Moon when on the Horizon)
In addition, the app allows you to see the Earth rendered either as a 3D globe or a 2D map using photo realistic texture maps for the Earth model (you can only zoom 2x due to texture map size limitations of the iPhone).
The orientation of the map is easily determined by a simple rotation of the device from portrait (3D) to landscape (2D). In either orientation you can zoom in and out as well as pan using the touch screen. Controls are given to allow you to select: the texture maps used, whether shading is performed, whether to draw political boundaries and if a lat/lon grid should be presented.
-- Feedback Answers/Notes --
All,
Some clarification on the features/capabilities.
-This is NOT a replacement for Google Earth (I purposefully have made it to work off the network as I use it for camping in the back country where there is no cell coverage) The graphics are not intended to allow you to zoom into great detail but rather to allow you to see which parts of the Earth are currently lit/dark.
-The Rise/Set times for the Sun and Moon have been checked against the Naval Observatory web site and appear to be accurate (within a minute). My guess is that there is confusion around Sun rise/set versus twilight (which is when the Sun is anywhere from 6 to 18 degrees below the horizon depending on the definition you want to use) The new version (already released) allows you to specify the elevation you would like to use (rather than hard wiring it to the horizon) Finally, if in using the app you have a specific location where the times do not appear to be correct please send me an email with the specifics and Ill run it to ground.
-AM/PM versus 24hr clock. Ill look into making that user configurable (seems like a reasonable enhancement request)
Thanks for the feedback and keep it coming.
-Craig