Satoshi HONDA is a Profesor at Department of Applied Phisycs and Physico-Informatics, Faculty of Science and Technology, Keio University. He received doctoral degree in Engineering from the University of Tokyo in 1985. He was a Research Associate at Department of Mathematical Sciences and Instrumentation Physics, University of Tokyo from 1975 to 1986. From 1986 to 1990, he was an Associate Professor at the Department of Mechanical Engineering, Faculty of Engineering, Kumamoto University. From 1990 to 1998, he was an Associate Professor at Department of Measurement Physics, Faculty of Science and Technology, Keio University. During these period in 1992, he was a Guest Researcher at Institut fuer Theoretische Elektrotechnik, RWTH Aachen. From 1998 to present, he has been a Professor at Department of Applied Physics & Physico-Informatics Faculty of Science and Technology, Keio University. His current research interests are inverse problems in measurement engineering. Research themes have been process flow tomography, MEG inverse problems, inspection of pipe wall thinning, calibration method in networked sensing sysytems, promotion of transdisciplinary science and its education, and so on. He is a member of the Society of Instrument & Control Engineering, Japan Society for Industrial & Applied Mathematics, and IEEE Signal Processing Society. As a specialist of measurement science and engineering, he is much interested in how to measure non-measurable.