Frequency resolution of a multi degree of freedom resonator

This paper outlines the process for estimating measurable parameters in a multi degree of freedom micro resonator. Thermal mechanical noise provides a baseline limit for frequency resolution of micro resonators. We develop the likelihood function for a linear regression model of 2 degree of freedom resonator. Using the Cramer-Rao inequality we determine the minimum possible covariance to estimate parameters, such as the natural frequency of the system.