GPS Upper-Air Sounding System

Huayuntianyi rolled out a system for the upper-air sounding device, with major indicators exceeding the criteria defined by WMO. In 2010, we attended the 8th WMO radiosonde intercomparison. The system composed of GPS radiosonde and ground data receiving system. The radiosonde is made up of four components: a GPS module, meteorological sensors, a radio transmitter and batteries. The GPS receiving module tells the position of the balloon in a real time manner, calculating out upper air wind directions and speeds. It collects air pressure/temperature/humidity data, and sends GPS and PTU data to the ground system. The ground system receives and processes the data, makes them into applicable upper air information.

Technical indicators

Temperature

       Sensor type: bead thermistor

       Measurement range: -90℃~50℃

       Resolution: 0.1℃

       Maximum measuring error: 50℃~-80℃  ±0.2℃ ; -80℃~-90℃  ±0.3℃

Relative humidity

       Sensor type: thin-film capacitor

       Measurement rang: 1%RH~100%RH

       Resolution: 1%RH

       Maximum measuring error: ±3%RH

Pressure

       Sensor type: silicon piezoresistive

       Measurement rang: 5hPa~1060hPa

       Resolution: 0.1hPa

       Maximum measuring error: ±1.5 hPa  (500hPa~1060hPa),

                              and ±0.7hPa  (5hPa~500hPa)

Wind speed

       Measurement rang: 0m/s~150m/s

       Maximum measuring error: 0.5m/s

Wind direction

       Measurement rang: 0°~360°

       Maximum measuring error: 3°

GPS receiver

       Horizontal position accuracy: ≤10m

       Vertical position accuracy: ≤16m

       Time to first fix: ≤60s（cold start）

       Recapture time: ≤10s 

Transmitter

       Frequency range: 400MHz~406MHz

       Output power: ≤23dBm

       Emission bandwidth: ≤20kHz(at -50dbc)

       Frequency stability: ≤20kHz(range of tem