A radiosonde (Sonde is French and German for probe) is a unit for use in things such as weather balloons that measures various atmospheric parameters and transmits them to a fixed receiver. Radiosondes may operate at a radio frequency of 403 MHz or 1680 MHz and both types may be adjusted slightly higher or lower as required. A rawinsonde is a radiosonde that is designed to only measure wind speed and direction. Colloquially, rawinsondes are usually referred to as radiosondes.
Modern radiosondes measure or calculate the following variables:
- Geographical position (Latitude/Longitude)
- Relative humidity
- Wind (both wind speed and wind direction)
- Cosmic ray readings at high altitude
Radiosondes measuring ozone concentration are known as ozonesondes.
Some photo taken during the search of a radiosonde.