Radiosonde is a specially designed Weather Instrument which is used for measuring temperature, humidity and the air pressure. The device is fit within a small box, which is carried into the upper layer of the atmosphere by a gas balloon. As it goes higher it measures and transmits the meteorological readings to the ground.

The temperature is measured with a thermometer the hygrometer measures the humidity and the barometer measures the air pressure. All of which are fit within the Radiosonde. The instrument is attached with neoprene balloons that are filled with helium. They are designed in a manner that they burst only after reaching a certain height and not before that. A Radiosonde can operate up to an altitude of 30,000 meters approximately from the ground.

The use of Radiosonde began during 1920s and 1930s by the investigators. The primary advantage of the Radiosonde is that the instrument is not required for collecting the data.

It rather transmits the measurements from the atmosphere itself. The Radiosondes are sent to the upper layer of the atmosphere by the meteorologists two a day during the noon and midnight following the Greenwich Mean Time.

A continuous measurement is taken by the device the more it is taken up higher by the balloon. The movement of the Radiosonde can also be tracked by special tracking equipment. Through this equipment the wind speed and wind direction data are also collected. The Radiosonde operates at 403 MHz or 1680 MHz radio frequencies and both of these can be adjusted according to the requirements.