The System Design Of Beidou Radiosonde Based On High-accuracy Temperature Sensor

The radiosonde is a high altitude meteorological data collection device, it usually carried by a weather balloon, rising to high altitude at a speed of 5 ? 6 m/s,and using internal sensors such as temperature sensor, humidity sensor, pressure sensor, wind speed and direction sensor to realise real-time measurement, then transmits the collected data to the ground through built-in wireless transmission unit,in order to satisfy the requirement of the people on the ground.Currently, bead thermistor sensor is the mainstream of high altitude meteorological observation temperature sensor carried by radiosonde, due to technical reasons and so on, the volume of bead thermistor sensor is usually at 1 mm level, which is not beneficial to improve the convective heat transfer capability.There's still a significant heating effect of solar radiation at high altitude.In this paper, an E-shaped high-accuracy temperature sensor based on 0.02 mm diameter platinum resistance wire used for high altitude measurement is proposed and developed, and a radiosonde system based on Beidou is designed. Using computational fluid dynamics (CFD) method to analyse the temperature sensor, then fit the results with Broyden-Fletcher-Goldfarb-Shanno (BFGS) method to get the radiation temperature correction equation. Beidou radiosonde system contains the air subsystem and the ground receiving system, the ground receiving system is consist of the ground receiver and PC software, it can achieve high altitude meteorological data collection, processing, transmission, display and record automatically.In order to test and verify the performance of the radiosonde, set up a test platform, the experimental results show that the solar radiation temperature of E-shaped high-accuracy temperature sensor is only 57% ?71% of bead thermistor sensor, the RMSE between measurement value and correction value is 0.013 K,which verifies that compared with bead thermistor sensors, the E-shaped high-accuracy temperature sensor designed in this paper can reduce the solar radiation temperature significantly, and the result also verifies the feasibility and accuracy of CFD method and BFGS method.Compared with traditional radiosonde, Beidou radiosonde system designed in this paper gains the advantages of higher localization and accuracy, more automatic and so on. It is believed that after further optimization and adjustment, Beidou radiosonde system can be used in weather detection and it is expected to replace the radiosonde made by foreign, it may realize digital detection and autonomy of high altitude meteorological equipment.