Scattering Property and Emissivity of a Periodic Pyramid Array Covered With Absorbing Material

Remote sensing systems must be calibrated before use, so the accuracy of calibration source has a significant effect on the property of the whole remote sensing system. In this paper, calibration sources constructed of a periodic metallic pyramid array covered with absorbing material are studied for remote sensing systems working in the microwave band. The scattering properties of this kind of calibration source are first analyzed by the Floquet theory and the spatial harmonic method. Then, the finite-difference time-domain method is used to simulate the calibration source structure to obtain the scattered field and the corresponding differential scattering coefficient. By integrating the scattering coefficient, the emissivity is finally obtained. The relationships between the emissivity and the pyramid array structural parameters, and the electromagnetic parameters of the covering material are given.