What is another word for pilot balloon?
Pronunciation: [pˈa͡ɪlət bəlˈuːn] (IPA) 
A pilot balloon is a small balloon that is used to test wind conditions, measure height, and provide information about the atmosphere. It is also known as an observation balloon, sounding balloon, or meteorological balloon. The pilot balloon is typically filled with helium or hydrogen and equipped with instruments that measure air pressure, temperature, and humidity. These balloons are often used in weather forecasting, aviation, and research. Other synonyms for pilot balloon include sounding rocket, radiosonde, aerological balloon, and upper-air balloon. The use of synonyms for pilot balloons depends on the specific context and application in which they are used.
