Vaisala's origins date back to the 1930s when Professor Vilho Väisälä, Vaisala's founder and long-time managing director, invented some of the operating principles of a radiosonde. The company was established in 1936 in Finland, and the first radiosondes were manufactured in the basement of a residential building in the center of Helsinki. From a modest start, the company evolved to become a world leader in many measurement fields.