Visibility Calculator TAB Use Visibility calculator to check the nearest visibility intervals for a given satellite. A satellite is visible when it is above the horizon and lit by the Sun. Press the Visibility Calculator button to open the Calculator window. Select a satellite from the drop-down menu, type in the date and the time you want and choose a calculation period. Click on the Calculate button. The calculation can take several seconds per each estimated day. When it has finished, select any visibility interval from the list and press the Set Time button. The Sky View will be reset to the beginning of the selected visibility interval. Close the Calculator window to return to the Sky View.