Alexander Dahl

[1][user-generated source] Alexander Dahl was born on 29 November 1892, in Barmen, today a part of Wuppertal.

Dahl was a reserve lieutenant World War I, where he received training as a free and tethered balloon observer and officer.

He was stationed in Dresden as part of Luftgau IV, an aerial reconnaissance group where he was able to contribute to the development of numerous radio related technologies.

The first image showing the Earth's curvature allegedly was taken at a height of 11,300 metres (37,100 ft) on 31 August 1933 from the high performance (9.800 cbm) hydrogen gas balloon Bartsch von Sigsfeld.

The official purpose of the flight was not to gain maximum height, but rather to measure the effect of sun radiation within the tropopause.