A weather station in Hongkong, every morning 8am, afternoon 2pm and evening 8pm start height sounding. Every time release a weather balloon with diameter 1m, carry radiosonde rise to sky, highest height can be 30km, in this procedure, radiosonde detect wind direction, wind speed, temperature, humidity and air pressure in different height and delivery this data back to ground. This data is important for ocean and aviation weather forecast.
You can buy a weather balloon from: Weather Balloon
You can buy a weather balloon from: Weather Balloon