Eight solar sensing cells comprise inexpensive monitoring instrument. Four cells always track Sun while other four face sky and clouds. On overcast day, cloud-irradiance sensors generate as much short-circuit current as Sun sensor cells. As clouds disappear, output of cloud sensors decreases. Ratio of two sensor type outputs determines fractional cloud cover.
Instrument measures cloud cover
NASA Tech Briefs ; 5 , 4
1981-04-01
Miscellaneous
No indication
English
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