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SQM/SQM-L Survey

Global Citizen Science

What is this?

Use a Sky Quality Meter (SQM) or Sky Quality Meter-L (SQM-L) to measure sky brightness in units of magnitudes arcsecond⁻² (mag arcsec⁻²).

The SQM/SQM-L is a handheld photometer that provides precise, objective measurements of sky darkness. Your readings join a global database supporting scientific research on light pollution.

Simply point at your zenith and record the reading.

Before you start:

• Ensure your SQM/SQM-L is calibrated
• Choose a clear spot away from direct light sources
• Point the device at the zenith (directly overhead)
• Record the digital display reading

I consent to my anonymous observation data (approximate location and sky measurements) being stored and used for scientific research into light pollution. I have read the Privacy Policy.