SQM-LE or SQM-LU as a Clear Sky Detector
The following example graphs reveal how easy it is to identify clear
skies using a Unihedron
recording readings once per minute.
Clear skies are indicated by smooth segments of measurements and
cloudy skies by rapidly changing values.
It is possible to sense the "churn" in real time and produce an
alarm when a sufficient string of smooth recordings (fainter than
some desired threshold) has occurred - indicating cleared skies.
The readings above were obtained in the town of Dundas, Ontario
mounted on the roof of my house.