Very interesting Luka! Must admit having been to BWCA many times I have only observed with binoculars at mostly overhead objects … many campsites have skies partially obscured by trees! The article's photos are great.
Wonder if Ann Schwaller, BWCA program manager for the Superior National Forest, used a sky quality meter like the Unihedron. https://optcorp.com/products/uh-sqm-l-sky-quality-meter-with-lens-sqm-l?gclid=CjwKCAjw4_H6BRALEiwAvgfzq_K_vwJVbFuZRWEc1hnY7uAdd_WLM10akMN_VieeOkVgq9fFToVZlBoCeygQAvD_BwE. I saw one in use at Newport State Park in Wisc. several years ago when the NCRAL was held nearby.