Sky Quality can be expressed in several ways.  The Unihedron Meter measures  Magnitude per square arc second (Mag/sq arcsec) and Naked Eye Limiting Magnitude (NELM).  

The term magnitude per square arc second means that the brightness in magnitude is spread out over an square arcsecond of the sky. If the SQM provides a reading of 20.00, that is equivalent to the light of a 20th magnitude star brightness spread over one square arcsecond of the sky.  

NELM is a theoretical calculation that estimates the dimmest star that can be seen unaided.  

The meter the meter updates every few minutes during night time and graphs the previous 24 hours. Archived data is available upon request.  By collecting this data, we hope to document the impacts of the surrounding areas on our night skies.


 SQM Readings
SQM Readings
 SQM Graph - Magnitude per square arcscond
SQM Graph
 SQM Graph - Naked eye limiting magnitude
NEM Graph