Palatinate Forest
The Palatinate Forest (, ), sometimes also called the Palatine Forest, is a low-mountain region in southwestern Germany, located in the Palatinate in the state of Rhineland-Palatinate. The forest is a designated nature park () covering 1,771 km and its highest elevation is the Kalmit (673 m).
Kalmit
Since 2012 there has been a special facility on the Kalmit for measuring visibility; its task is to record visibility in the Palatine Forest-North Vosges Biosphere Reserve. Whilst at many, unmanned, weather stations, visibility measurements are made automatically for the range 0 to 10 km which is relevant to traffic safety, the measurement station on the Kalmit is designed for the range 10 to 390 km, which is relevant in assessing the fine dust content of the air. Measurements and survey photographs are obtainable through the "Fern-Sehen Project" ("Projekt Fern-Sehen") in the Palatine Forest, which is managed by the House of Sustainability in Johanniskreuz, a department of the Rhineland-Palatinate State Forestry Commission. Another feature is that the values were introduced to alert nature lovers, because exceptional visibility is very rare and difficult to forecast.