Research On Key Technology Of Radiosonde System And Implementation

Atmosphere aloft observation is play important role in revealing atmospherestructure, constructing a theory of atmospheric sciences, and improving theaccuracy of weather forecast. The paper is systematically studied radiosondesensor design, measure method, date process and fusion method, in order toimporve the measurement accuracy, reduce measurement error, reducemanufacturing cost, and enhance the international competitiveness of domesticradiosonde system. The main study works are as follows:1. In order to verify the practicality and scientific of radiosonde keytechnologies which are studied, the radiosonde system using microwavecommunication method and GPRS communication method according to therequirements and technical characteristics are designed. Data process method andmain parameters calculation method of static measurement characteristics in thestatic experiment are studied. The ground dynamic experiment instruments aredesigned and studied the ground and high altitude experiment methods.2. Aiming at the humidity sensor is easy to condensation and can not workunder the high altitude environment, a sandwich plate capacitive humidity sensor,integrated with a snake like platinum resistance heater was designed. Thetemperature distribution of sensor surface and the function relationship ofenvironment temperature, heating power and heating temperature were got usingfinite element analysis. Using four humidity sensors to build the sensor array, inorder to avoid the atmosphere aloft measurement failure because of harshenvironment and small group of turbulence damaged to humidity sensor, andimprove fault tolerance and complementary of humidity detection.3. Aiming at humidity fluctuation and the board distributed capacitance canaffect measurement results, and so on, the humidity measurement circuit isdesigned using capacitor charging and discharging measurement method and capacitor comparative measurement method. A weighted average and batchestimates multi-sensor data fusion algorithm are studied, compared with thearithmetic average data processing method which is currently used, the methodnot only has strong fault tolerance and complementary, but also has goodreal-time performance. The ground measurement characteristics experiments arecarried out, and got the humidity sensor static performance and time constant.The humidity sensor measurement characteristic experiments were carried outunder low temperature condition and get the sensor performances. Theatmosphere aloft measurement mode was established by heating humidity sensorunder low temperature condition.4. Aiming at the temperature sensor has long response time problem atpresent, AC comparative temperature measurement method is studied, and usingplatinum resistance wire which the diameter is about2.5μm as temperature sensor,the method can improve the signal to noise ratio effectively, eliminate zero driftand temperature drift, and solve the sensor base value influence due to the circuittrace on the board. The temperature datas were processed using harmonicanalysis, in order to filter the quantization noise which was generated by A/D,and reduce the high frequence noise and Gaussian white noise influence underhigh altitude condition. Simulation results demonstrate the method effectiveness,and establish the atmosphere aloft measurement mode.5. One radiosonde atmosphere aloft measurement experiments were carriedout, and demonstrated the system measurement performance and electricalperformance; system comparison experiment were carried out, the experimentsresults demonstrated that the system meet the requirements of the nationalmeteorological observation network and the world meteorological organization.The study results provide the technical foundation for the further engineeringapplication.