Table 3 Performance of atlas predictions for different data sets.

Negative values indicate that the observed skies were brighter than predicted. The top entries are used to calibrate the atlas. The final three entries are independent data sets used for verification. PS, professional scientist; CS, citizen scientist.

ProviderLocationModeMeanσScientist
All dataWorldwideBoth0.0080.17Mixed
VariousCatalonia, SpainCar0.030.14PS
Universidad Complutense de MadridMadrid, SpainCar−0.040.17PS
Kyba/SanchezBerlin, GermanyCar0.120.11PS
Globe at NightWorldwideHand−0.210.34CS
Haenel/FrankEurope and North AmericaHand0.050.17PS
UnihedronWorldwideHand−0.010.24CS
Loss of the Night appWorldwideHand−0.020.29CS
Espey/OwensIrelandHand−0.080.14Mixed
Royal Astronomical Society of CanadaCanadaHand−0.010.28CS
GiubbiliniItalyHand0.030.09PS
International Dark Sky PlacesWalesHand0.010.27CS
U.S. National Park ServiceUnited StatesCCD0.110.13PS
FalchiItalyCCD−0.040.19PS
SQM stationsWorldwidePermanent stations−0.060.46Mixed