24
4.5.2
"Two-oscillators, two-channels" mode
It is the modification of "two oscillator" mode that uses two identical measuring
channels to reduce the measurement channel error. Same signals are fed to "
fx" and
"
fy" inputs of both channels (see Figure 6). Thus there is a duplication of the
measurement results. And the measurement error introduced by the channel can be
reduced using cross-correlation processing. The channels noise can be estimated along
with the measured signals
instability. Accuracy of estimations depends on the
measurement time interval.
Table 4 shows mathematical expectation of calculated functions for the
measuring channels pair – CHANNEL 1 and CHANNEL 2. These functions estimate
bias caused by instability of channels and reference signal.
