Sparse Emission Source Microscopy for Rapid Emission Source Imaging

Emission source microscopy (ESM) technique can be utilized for the localization of electromagnetic interference sources in complex and large systems. This paper presents a sparse and nonuniform sampling technique for ESM. Compared with the traditional way of acquiring abundant and uniformly distributed scanning points on the scanning plane using a robotic scanning system, the proposed method is much more time-efficient in identifying the major radiation sources, even though the image quality is sacrificed. The feasibility of sparse sampling is mathematically proved, and it is shown that increasing number of scanning points increases the signal-to-noise ratio of reconstructed images. Besides, a nearest neighbor interpolation method is applied in the real-time processing to estimate the radiated power through the scanning plane. Thus, back-propagated images and estimated radiated power can be obtained in the real-time measurement process, which can efficiently and instantaneously provide the locations and the radiation strength of the most significant emission sources.