VIEWS

Satellites has two main views: "Global" and "Predictions"

In the "Global" view, the Earth is displayed with the paths of satellites.
The view can be reoriented by rolling the globe using a finger, and it can be zoomed in and out with two fingers to accommodate a wide variety of views. At the top of the screen, left and right, are two icons that can be tapped to change the orientation to be centered on the ISS or the observer, respectively.

The path the satellite follows around the Earth is shown as a solid line where the object is in sunlight, and as a dotted line when it is in the Earth's shadow. The satellite will be visible to the observer when it is illuminated by the Sun and the observer's sky is dark -- this means visible passes can only happen in the couple of hours before sunrise and after sunset. The circle around the satellite's location represents the surface within which the satellite will be visible and its radio signals heard.

When the ISS is centered in the view, its latitude, longitude and height above the Earth will be displayed. If the view is centered on the observer, and the ISS is close, two things happen -- one is three yellow circles appear around the observer within which the ISS will be visible (representing 10°, 20° and 45° above the horizon), the other a display of the ISS location in terms of where it will be in the sky and how far away it is.


The "Predictions" view is a list of all the passes of the ISS over the observer's location. Each pass is annotated to indicate as much information as possible.

First the background color of each row indicates the color of the sky -- ranging from white (daylight), through two colors of blue (early and late twilight), and black (night). The daylight passes will not be visible because the sky is too bright and the night passes will not be visible because the ISS is not illuminated, but these passes will be interesting for those people who listen in for ISS communications with the ground.

The twilight passes are those for which the observer may be able to see the ISS in the sky, assuming the pass is not too extreme and the cooperation of the weather. Each row carries information about the nature of the pass -- for example, the last pass on July 14 starts illuminated, rising in the West-South-West at 10:33pm; reaches a maximum elevation of 7° and then sets in the South-South-West about 10:36pm. This pass in in mid-twilight, so the sky will be moderately dark, but since it reaches less than 10° above the horizon it would be a very challenging pass to observe.

It is often difficult to catch the beginning of an evening pass -- the ISS is rising out of the western sky nearest the sunset, it is about 1500Kms away and the sun is shining on the side of the ISS away from you. Until you gain some experience, you'll likely not catch ISS till it's quite high in the sky.