A basic property of a measurement process is that repeated observations of the same quantity will not give identical results due to the presence of random errors. In order to assess the effects of random errors in our measurement process, we need to build in redundancy. This paper presents a brief summary of the statistical methods used to evaluate the random errors in dual six-port measurements of reflection coefficient and scattering parameters.
Robert M. Judish, Glenn F. Engen, "On-line accuracy assessment for the dual six-port ANA: Statistical methods for random errors," IEEE Transactions on Instrumentation and Measurement, vol. 36, no. 2, pp. 507-513, June 1987.
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