Emissivity calculation of finite-size object

In application, the microwave remote sensing system must be calibrated at first by a reference source with known emissivity, which is also called the calibration source or blackbody. Therefore, to estimate the emissivity of the calibration source is a very important work. However, for a finite-size calibrator, the method capable of accurately calculating its emissivity has not been reported before our work. This paper presents our efforts in finding the accurate calculation methods of the emissivity for finite-size objects. Some findings in this paper might also be helpful in understanding of the power interactions between the matter and the wave.