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(1) What is a radiosonde and how are the data it provides used?

NWS has been using balloon-borne radiosonde instruments since the late 1930's. The data they provide are critical for weather forecasting and research. Click here to learn more.

(2) I found a radiosonde. Is it dangerous? Does the National Weather Service want it back?

If you found a radiosonde, follow the instructions here: Found Radiosonde Instructions

(3) What types of radiosondes does the NWS use in its network?

Lockheed Martin (LM)  LMS-6 radiosonde (1680 and 403 MHz) and the Vaisala RS92-NGP radiosonde

(4) What types of ground equipment does NWS use to track the radiosonde?

All stations use GPS radiosondes operating at 1680 MHz or 403 MHZ. 

(5) How are radiosonde data checked for quality?

Quality control of radiosonde data is done at the upper-air station and national centers such as the NOAA National Centers for Environmental Prediction (NCEP) and at the National Centers for Environmental Information (NCEI). 

(6) Why does NWS still use radiosondes? Isn't there another observing system available that can provide the same data?

Presently, no single observing system (e.g., satellites, aircraft observations, and ground-based remote sensors) can match the vertical data resolution (about 5 meters) and height coverage (more than 30 km) obtained with radiosondes. 

(7) What is the difference between a radiosonde and a rawinsonde observation?

A radiosonde observation provides only pressure, temperature, and relative humidity data. When a radiosonde is tracked so that winds aloft are provided in addition to the pressure, temperature, and relative humidity data, it is called a rawinsonde observation. Most stations around the world take rawinsonde observations. However, meteorologists and other data users frequently refer to a rawinsonde observation as a radiosonde observation.