I think that the balloons did not become obsolete because they gather informatio in a different way than weather sattelites. They are used to check the information and make sure that it is correct. A weather or sounding balloon is a balloon (specifically a type of high altitude balloon) which carries instruments aloft to send back information on atmospheric pressure, temperature, and humidity by means of a small, expendable measuring device called a radiosonde. To obtain wind data, they can be tracked by radar, radio direction finding, or navigation systems (such as the satellite based Global Positioning System also known as a GPS).
I think that the balloons did not become obsolete because they gather informatio in a different way than weather sattelites. They are used to check the information and make sure that it is correct.
A weather or sounding balloon is a balloon (specifically a type of high altitude balloon) which carries instruments aloft to send back information on atmospheric pressure, temperature, and humidity by means of a small, expendable measuring device called a radiosonde. To obtain wind data, they can be tracked by radar, radio direction finding, or navigation systems (such as the satellite based Global Positioning System also known as a GPS).