Research On Control Of Small Microwave Radiometer System Based On UAV Platform

The spaceborne microwave radiometer is an important equipment for observing the Earth and the atmosphere in space.In order to verify the scientific data of Earth observation by the spaceborne microwave radiometer,it is necessary to synchronized the observation between satellite and ground through the aeria-test,obtaining airborne microwave radiometer data to verify the spaceborne data.Compared with the traditional airborne microwave radiometer,using microwave radiometer based on the small UAV platform for earth observation can collect the earth observation data more conveniently,and has better spatial resolution.This paper based on the application requirements of the UAV-borne microwave radiometer,and study its system structure,data acquisition and system control in depth.The main contents are as follows:(1)Provided a solution of the UAV-borne microwave radiometer system,and describe the system composition and parameters in detail.The frequencies of the radiometer are selected at 10.65,18.7,23.8,36.5 and 89 GHz,all of which are designed dual-channel with both horizontal and vertical polarization,and are used to detect brightness temperature and soil moisture of ground objects.In order to adapt to the small UAV platform,weight,power consumption and size of the radiometer system must be reduced.The direct detection system is adopted for each channel as an replacement of the traditional superheterodyne receiver,and realizes the miniaturization of the radiometer system.(2)Aiming at the application requirements of the UAV-borne microwave radiometer,this paper proposes a design for the data acquisition and system control unit of the UAV-borne microwave radiometer,and completes the system circuit.The system includes the function of data acquisition of the radiometer receiver’s output,the control of calibration and observation mode,GPS positioning,temperature measurement,and data storage.And the component selection and design method of each circuit module are introduced in detail.(3)Design and develop the system control software.The system observation process is given according to the observation mode and observation period,and control function for each unit are achieved at the same time.The hierarchical structure and modular design method of the system control program are also introduced.In this way,data acquisition,system mode control and data storage are completed.(4)Design and develop the PC user interface.The development of software is based on MATLAB App Designer,and the output data are stored in HDF5 format,which achieve the analysis,processing and plotting of the data,and the computer-human interaction interface is friendly.Finally,the tests of data acquisition and system control unit was implemented.The results show that the data acquisition,system mode control,temperature measurement,and data storage functions of the system are running normally,and the states are stable,which lays the foundation for the development and integration testing of the UAV-borne microwave radiometer system.