A picture showing the components of radiosonde apparatus.
Figure 1: This picture shows the apparatus that is required for a radiosonde ascent. In this particular case, several radiosondes are suspended from a test rig under one helium balloon. The sonde carries a radar reflection shield so that the wind speed and direction may be calculated by means of radar. (See windfinding equipment). When the balloon bursts, the instruments are returned to the surface by parachute.