Research On Microwave Radiometric Characteristics For Typical Ground Objects

Both passive microwave remote sensing and accurate guidance depend on microwave radiometric characteristics for ground objects. The research of the microwave radiometric characteristics for typical ground objects can offer fundamental theory, measurement method, experimental data for them. On the basis of microwave radiometric characteristics measurement principle, this paper carries on the research of microwave radiometric characteristics for typical ground objects on theory and experiment in some degree. According to the basic principle of microwave radiometric characteristics measuring, the Microwave Radiometric Characteristics Measuring and Processing System (MRMS) was developed. It can measure microwave radiometric characteristics for Ground Objects, and inverse the brightness temperature from the objects' antenna temperature. Furthermore draw the experimental model of objects utilizing curve-fitting method.According to radiometric transmitting theory, objects can be considered as multilevel mediums. Based on the geometry characteristic, dielectric properties, and temperature distribution of every layer medium, it can calculate the reflective rate and emissivity(or equivalent emissivity) of targets. After achieving the bright temperature or apparent temperatures of below the objects surface, the brightness temperature or apparent temperature of the objects is gained by multiplying by emissivity( or equivalent emissivity). This is the theory research method of microwave radiometric characteristics. In this paper, the theory model of sunny sky and smooth surface of water was proposed.In order to adopt the experiment method to carry on the research on microwave radiometric characteristics for typical ground objects, a large amount of microwave radiometric characteristics data is required. Microwave radiometric characteristics for typical ground objects is measured for this reason. At the same time, present the method that achieving brightness temperature from antenna temperature adopting Fourier-Transform recursion method, and discuss how to acquire the experimental models of antenna temperature or brightness temperature with changing of angle and temperature using two-variable polynomial curve-fitting on the basis of working in the front.