We then repeat the analysis for regions of interest distributed over the proof mass. The estimated displacements of each region are indicated in this image with dots. Measurements were repeated at many different stimulus frequencies to determine the frequency response for in-plane rotation. Measurements were also repeated for different stimulus amplitudes at the resonant frequency. The line given by the equation at the top of the plot is a regression line fit by a least squares method.
Pluses indicate the standard deviations of results at each amplitude.
Three dimensional regions of interest were constructed by stacking corresponding regions from each plane of focus. Such a stack of four planes is shown in the lower left part of this figure. We can again illustrate our motion measurements with dots. But now the dots move in three dimensions. We can look down on the dots to see in-plane motions, as shown in the upper part of this figure.