Report of the 2015 LoNNe Intercomparison Campaign

The 2014 LoNNe (Loss of the Night Network) intercomparison campaign is the third of four campaigns planned during EU COST Action ES1204. The first campaign took place in 2013 in Lastovo, Croatia, the second in Madrid, Spain. This year's campaign continued the strategy started last year, of taking measurements at two sites, an urban location and a village. The main goals of the campaigns are to: o Understand the systematic uncertainty of skyglow measurement instruments. o Examine the differences and similarities between different types of measurements, and understand under what circumstances results can be converted or compared. o Quantify the sky brightness at the selected sites. This report provides a brief synopsis of the campaign and its preliminary outcomes. Section 2 describes the measurement locations, the activities of the participants, the instruments used, and the environmental conditions. Section 3 describes a public outreach event held during the campaign. Section 4 provides some preliminary results, outlines the ongoing analyses, and presents research questions for the next campaign to address. Section 5 provides recommendations for the final LoNNe intercomparison campaign in 2016. Section 6 concludes the report.