Papers by Author: Yu Zhang

Abstract: The paper introduces a widely used atmospheric absorption models: MPM by Liebe in 1989. Using this absorption model, the paper simulates the temperature and humidity weighting functions and brightness temperature according to the different frequencies and bandwidth of the multi-channel ground-based microwave radiometer. The results show that simulated brightness temperatures are very well agreement with the observation values with an acceptable root mean square error. This paper uses widely used retrieval method of artificial neural network to obtain the water vapor density profiles and calculates the root mean square error of each dataset. Also, to improve the accuracy of retrievals, this paper adopts multi-layers neural network which has two hidden layers. The results show that the retrievals of water vapor density profiles based on ground-based microwave radiometer are agreement with the water vapor density profile which is observed by radiosonde. Grant Nos. GYHY200906035 China Meteorological Administration nonprofit sector (meteorology) special research

Abstract: Microwave emissions at various frequencies are known to contain information on atmospheric chemistry. Information about water vapor is of great interest at 183.31GHz. Interferometric synthetic aperture radiometer avoids the disadvantages of manufacturing and carrying large antennas at the expense of complexity. This paper has discussed the design of the 183.31GHz interferometer system with two elements based on imaging theory and retrieving algorithm of two-dimensional synthetic aperture radiometer. And then several important experimental results are presented.

Abstract: A new sensor-based temperature measuring system with high accuracy is presented in this paper. The temperature accuracy smaller then 0.02K is the measured performance of the measuring system after calibration at ten temperatures, over the -50°Cto 300°C targeted temperature range. Comparing with the traditional temperature measuring system, the advantages of the new sensor-based temperature measuring system are the high precision, immunity to noise, independent with the length of sensor wires and remote operation. And all these are at a low cost with less then 36mW of power consumption. Therefore the sensor-based temperature system is suitable for any field where reliable and accurate temperature measurement or a wide measurement range is necessary.

Abstract: This paper investigates the mobile phone’s interference to the 183.31 GHz receivers of the MWHS (Microwave Humidity Sounder) in the FY-3 Meteorological Satellite by a set of related experiments, by which way finds the interfering path. And it analyses the influence of the mobile station’s interference to the orbiting Space-borne Microwave Radiometer in theory. The factors related to the jamming distance and their forces are analyzed. The way to prevent and resolve the interference is proposed and it has been proved by the experiment.