Lifetime Performance Analysis of a Hyperspectral Imager Based on a Piezoelectrically Tunable Fabry-Perot Interferometer

The calibration stability of miniature spectral imagers based on a piezolectrically tunable Fabry-Perot interferometer (FPI) has not been previously examined in long-term use. These instruments are increasingly launched to space, for example on the Kuva Space’s Hyperfield-fleet of Earth observation satellites and with the ESA Hera asteroid mission. Difficulty of re-calibration in a space environment means that prior knowledge of possible calibration drift is invaluable. In this study, we examined the performance of an FPI imager that was used for nine years in a hospital environment. We analyzed images gathered during the use of the imager, looking for systematic errors. A degree of drift in the results was found, but we could not determine whether it was caused by imager degradation or changes in the measurement setup. We also performed new characterization measurements for the imager. Based on the measurement results, the FPI control circuits’ response to setpoint values sent to them appears to have changed. This error could be caused by a leak in the hermetic seal around the FPI. Repeated measurements showed similar results, indicating that the imager performance is consistent.