There’s an article about Windsond in the 2013 autumn edition of the Swiss Ballooning magazine Contact. It makes a detailed comparison between Windsond and the method of finding wind directions by manually aiming a measurement device, theodolite, towards a small rising balloon and sending the observed angles to a computer.
The author finds that the theodolite method lacks in reliability since it relies on the rising balloon to maintain a constant rise speed. As Windsond demonstrates, this is not always the case. There’s one disadvantage to Windsond — sudden changes in conditions between two layers of air are diluted by the smoothing of data samples by the Windsond computer software. In response to this, I’ve now developed a more sophisticated algorithm which detects and preserves sudden changes. After testing and optimization, this will be released to all customers.
The magazine is in German. See the Windsond article as pdf. The magazine also mentions how Windsond was used in the European Ballooning Championships 2013 (article as pdf). Or see the full magazine as pdf, from the Swiss Ballooning Association (SBAV).