We will establish this Sky Quality Monitoring Program to monitor the darkness of the night sky in Ivins Utah. This will allow us to assess the effectiveness of future light pollution mitigation efforts in the city. The monitoring program may also be used to support an application to International Dark Sky Association for certification as a “Dark Sky Community”.
Equipment
The monitoring program will utilize a Unihedron Sky Quality Meter (SQ-L). This meter measures the darkness of the sky in magnitudes per square arcsecond (mag/arcsec). This is a logarithmic measurement which means that large changes in sky brightness correspond to relatively small numerical changes. The meter’s range is roughly 16 to 23. Lower numbers indicate more light pollution. Higher numbers indicate darker skies. Readings over about 20.00 indicate “dark skies”. The SQ-L is not affected by temperature and is typically accurate to ±0.10. The SQ-L has a field of view of 20°. The meter’s model number is _2.18 and the serial number is 7914.)
Measurement locations
Nine locations have been identified in Ivins to take regular sky quality measurements. These locations are shown on the attached map and identified by description and latitude and longitude on the attached Sky Survey Data sheet. The locations were chosen to contain a mix between sites on the edge of the City likely to have darker skies and sites in the middle of the City likely to have brighter skies. Over time, review the readings at each location to see if any locations are redundant.
Timing
The initial base line sky quality measurements took place on December 30, 2018. Thereafter, measurements will normally be taken two to four times a year.
Technical notes
We make measurements using the SQM-L Sky Quality Meter by Unihedron. This is a narrow cone, sensitive low-level light meter recommended by the International Dark Sky Association. It is Model No. _2.18, Serial No. 7914.
Participate
If you would like to get involved in this project, let us know. Send us an email from the Contact us page.
Check this “Activities” section of our website regularly for new activities that may interest you and for updates on our progress.