Jan 2010

Happy New Year

It's time to get Satellites 1.2 released. It has undergone several changes during the development phases for version 1.2 and is now ready to be shipped to Apple. The application now boasts two views: a 'global' view which is similar to previous versions, and 'predictions' view to display upcoming passes.

The global view offers a slider to 'fast forward' and 'rewind' the clock, with a display of the simulated time, and two 'buttons' at the top of the screen to change the orientation of the globe -- either centered on the ISS or centered on the observer. In either case that orientation can be changed by swiveling the Earth using touches of the finger.

The global view will show up to three satellite tracks. The ISS is always displayed; a Shuttle's track will be displayed if it is flying; and the track of the Hubble Telescope can be turned on in the Settings. These tracks show as solid lines when the object is in sunlight and dots when it is in shadow. There is also a setting to enable the display of the 'twilight zone!' If the observer is in this zone, satellites are likely to be visible shining in the dark sky.

The predictions view shows a list of upcoming passes -- times when the ISS is above the observer's horizon. This is a necessary, but not sufficient, condition for visibility -- if it's daylight or late at night the ISS will not be visible. Each pass is represented in a way that predicts its visibility.