Design Of A Reference Radiosonde Based On ARM Processor

Radiosonde usually carry the temperature sensor which have characteristics of good transient, humidity sensor, pressure gauge, GPS positioning module and wireless transmitting module components. It is carried on a rising balloon. The speed of balloon is 5?6 m/s. Radiosonde is used to detect the upper air parameters such as temperature and humidity, air pressure, wind speed and direction. A reference radiosonde system based on a high-precision thermometer and an ARM processor is proposed. The system includes an airborne subsystem and a ground-based subsystem. The airborne subsystem includes an array-based sounding temperature sensor. A variety of meteorological sensors, such as dew point hygrometer and pressure sensor, can be integrated.Array-based sounding temperature sensor consists of platinum resistance thermometer, an array of four thermocouples and a precision measurement circuit. A computational fluid dynamic method is utilized to simulate the array-based temperature sensor. Simulation results suggest that the new design helps to reduce the solar radiation error resulted from heat contamination. And the rationality of the sensor's design is verified preliminarily. A low-air-pressure experiment platform is constructed to simulate high altitude environment. And the simulation results are compared with the simulation data. Experimental results indicate that if a single thermocouple is used as sounding temperature sensor, the solar radiation error error resulted from the heat contamination considerably will be 8.13%?41.65%; if an array of four thermocouples are used as sounding temperature sensor, the solar radiation error resulted from the heat contamination considerably will decrease to 0.43%?8.72% The difference between experimental results and simulation results are -3.02%?5.44%, which shows that the experimental results agrees with the simulation results.Reference radiosonde can connect the precision dew point and pressure sensor. Mounting the sensor under test in the same balloon with the reference radiosonde together, can complete various sounding sensor's comparison test in the high altitude, which can test the error characteristic of sounding sensors. The reference radiosonde system, compared with the traditional radiosonde, features high precision of temperature observation, low noise, and high extensibility. This radiosonde system is expected to be used in high precision climate sounding and meteorological disaster early warning in the future, after further improvement.