Støjkort round (no key): which mapping round the noise-map tiles are drawn from right now, and its bands per source

runde is 2022 (the Danish calculation, Nord2000, drawn from Grundfast’s own copy of Miljøstyrelsen’s download) once that round is loaded, else 2017 (Miljøstyrelsen’s own tiles). The two rounds have different classes — 2017: 55–59 … 75+ dB Lden for both sources; 2022: 53–57 … 73+ for roads, 54–58 … 74+ and 79+ for rail — so skala gives, per source, the lower bound, label and pixel alpha of every band. Pin tile URLs to this round with ?runde=.