Unihedron Sky Quality Meter (Ethernet)

The Unihedron SQM-LE is an ethernet enabled version of this popular Sky Quality Meter. It is supplied with cables and PSU to allow it to connected simply to an existing wired network. It can in addition be connected directly to a computer with the supplied cross-over cable, thus allowing easy use within an observatory if the observatory PC is connected via Wi-Fi.

Software supplied with the SQM-LE allows it to be easily dicovered on a network and configured. The free SQM Reader software provides realtime measurement of sky brightness.

Uses:

• Find out how good the night or site REALLY is.
• Compare the sky brightness at different sites quantitatively.
• Document the evolution of light pollution in your area.
• Set planetarium dome illumination to mimic the skies people are likely to experience elsewhere in the city.
• Monitor sky brightness through the night, night-to-night, and year-to-year.
• Determine which nights show the greatest promise for finding the 'faintest fuzzies'!
• Calibrate the effect of sky brightness on qualitative measures such as the Bortle Scale.
• Investigate how sky brightness correlates with the solar cycle and month-to-month sunspot activity.
• Help provide local ground truth for future sky brightness prediction with the Clear Sky Clock.
• CCD users can make a correlation between the SQM reading and when the background reaches a specific ADC level.

Features:

• Sky brightness reported in visual magnitudes per square arcsecond.
• Infrared blocking filter restricts measurement to visual bandpass.
• Sensor temperature, model number, and serial number are provided.
• Precision readings at even the darkest sites.
• Field-upgradeable firmware
• Open protocol document

Specifications:

• Ethernet connectivity
• Included applications for reading data in Java, C, Perl, Python.
• The Half Width Half Maximum (HWHM) of the angular sensitivity is ~10°. The Full Width Half Maximum (FWHM) is then ~20°. The sensitivity to a point source ~19° off-axis is a factor of 10 lower than on-axis. A point source ~20° and ~40° off-axis would register 3.0 and 5.0 magnitudes fainter, respectively.
• Operates from 5-6VDC adapter (included).
• Size 3.6" (91.44mm) x 2.6" (66.04mm) x 1.1" (27.94mm)
• Maximum light sampling time: 80 seconds.
• Minimum light sampling time: 1 seconds.
• Specifications are subject to change without notice.