Once all of the needed supplies are gathered for the flight, the observer will turn on and power up the Radiosonde Replacement System (RRS). This is typically done thirty minutes before launch time, or even earlier if cold weather conditions are present. The RRS consists of the observing computer, an antenna which is housed in a radome, a remote unit for controlling the antenna, and a surface based observing weather system.
RRS User Interface Display Screenshot
Upper Air Building and RSOIS Tower
Upper Air Antenna Located Inside the Radome
The Helium Tank Storage Room
Inflation Lifting Column and Weights
The observer must calculate the appropriate amount of lift for each sounding depending on the surface and atmospheric conditions present. This is achieved by using a weight system in order to attain the desired 4.7 - 5.2 m/s for the ascent rate. When high winds or precipitation are present more lift (helium gas) will be added to the weather balloon in order to achieve the desired ascent rate.
As the balloon is being filled with the desired amount of helium gas, the observer creates the sounding train by measuring the appropriate amount of string, attaching the parachute, and/or train regulator if necessary. Once the balloon has achieved its desired lift, the flow of hydrogen gas will shut off automatically. Then the observer securely ties off the weather balloon and attaches it to the sounding train. Once all of these steps are completed the weather balloon and sounding train are ready to be launched.
Weather Balloon With Inflation Complete