Tools: The Globoscope

Say you want to evaluate a piece of land for its solar potential.  Maybe it's surrounded by buildings or trees.  You can use a device called the Solar Pathfinder (see below).  It essentially reflects the surrounding features to create a map of the sky—a hemispherical projection—corresponding to all the hours of the year.

I believe the Solar Pathfinder is a direct descendant of the Globoscope, an instrument created by Swedish architect Gunnar Pleijel in 1947.  Pleijel described the Globoscope in 1963 as "a paraboloidal mirror with a vertical axis of revolution, which is photographed from above through a lens."  The "little-known device" was resurrected by Penn State researchers in a 1977 paper in Solar Energy.

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