Electronic cooling of resonant gravity gradiometers

Electronic cooling for improving the signal-to-noise (S/N) performance of sensors was applied to the mechanically resonant Hughes rotating gravity gradiometer (RGG). An 8.3-dB improvement in the S/N was obtained. The electronic cooling technique uses a negative feedback damping circuit between the two RGG transducers. The feedback circuit is electrically equivalent to a high-impedance resistor cooled to cryogenic temperatures.