Dr. John Barentine FRAS<p>New paper from the U.S. National Park Service Natural Sounds and Night Skies Division: "Fisheye Night Sky Imager: A Calibrated Tool to Measure Night Sky Brightness" <a href="https://iopscience.iop.org/article/10.1088/1538-3873/ad6bc1" rel="nofollow noopener noreferrer" translate="no" target="_blank"><span class="invisible">https://</span><span class="ellipsis">iopscience.iop.org/article/10.</span><span class="invisible">1088/1538-3873/ad6bc1</span></a> (open access)</p><p><a href="https://astrodon.social/tags/LightPollution" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#<span>LightPollution</span></a> <a href="https://astrodon.social/tags/DarkSkies" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#<span>DarkSkies</span></a> <a href="https://astrodon.social/tags/NightSkyBrightness" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#<span>NightSkyBrightness</span></a> <a href="https://astrodon.social/tags/Conservation" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#<span>Conservation</span></a> <a href="https://astrodon.social/tags/Instrumentation" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#<span>Instrumentation</span></a></p>