Franz Ludwig Pfyffer's Relief of Central Switzerland: a digital documentation and aspects of modern surveying
Cartographica Helvetica 26 (2002) 31–35
Between 1762 and 1786, lieutenant general Franz Ludwig Pfyffer von Wyher (1716–1802) constructed a relief of Central Switzerland. This three-dimensional masterpiece with a size of 3.90 x 6.70 m displays the area of Lake Lucerne with neighbouring cantons in a scale of about 1:11,500. The relief is an extraordinary topographic and cultural achievement of international significance and a pioneering work of Swiss cartography.
Applying the principles of photogrammetry, a precise 3D model of Pfyffer's relief has been created for the documentation of cultural heritage. The digital terrain model as well as the high-resolution orthoimage allow the first quantitative accuracy analysis of the relief. The reconstructed relief part deviates from the current maps about 180 m in the plane and 63 m in height. The related old maps have been analyzed as well, as they may provide hints about the sequence of Pfyffer's work. The relief is based on Pfyffer's own measurements performed during 24 years. According to new investigations, his surveying procedures turn out to be much more systematic than previously assumed. The high accuracy of his results was mostly achieved by means of good organization and many repeated measurements.