SOS is a room-sized display system that uses four projectors to display planetary
datasets on a 6 foot diameter sphere. The projectors are located about 17
feet away from the center of the sphere and are mounted approximately 90
degrees apart from each other. Each projector displays a portion of a dataset
(which is either an image or a video) onto its quadrant of the sphere.
Light from adjacent projectors overlap and create edges in these overlap
regions (also called blend regions). This causes the appearance of disjoint
images in the areas of overlap. Projector alignment is the process that allows
a dataset to be displayed by four projectors such that the dataset appears as one
continuous image wrapped around the sphere, rather than four disjoint images.
If this is the first time you are doing alignment, you will need anywhere from
1 to 2 hours to complete the alignment process. For first time users, it takes
some practice, so be patient. If you have done alignment before, or if the
alignment is just being tweaked, the process may take anywhere from 15 minutes
to 1 hour to complete, depending on what point in the process you are starting
To perform projector alignment for an SOS installation, you need to have access
to the main SOS computer. (For sites that are still using the 5-computer
system, you will only need access to the main SOS NC computer.) In order for
alignment results to be saved, you must be logged in as user “sos”.
You need to have an iPad installed with a copy of the “SOS Remote” (the iPhone
or iPod Touch also supports alignment, but these devices are deprecated). This
app is available for free download from Apple’s App store. You will need Wi-Fi
or Bluetooth access to connect your mobile device to the SOS computer.