Upper-air weather soundings by radio

A radio system for upper-air weather soundings with small unmanned balloons is described. The balloon instrument comprises elements for measuring pressure, temperature, and humidity, and a miniature radio transmitter; the latter converts the response of the measuring instruments into characteristic signals modulating the emitted radio wave and sends this wave to a ground station where the signals are measured and recorded. Details of the system are given and a discussion is given of the accuracy of the upper-air observations obtained and of the tolerances permissible for component elements of the system.