Vibration Induced Tilt Error Model for Aircraft Interferometer Data

摘要

The Scanning High-resolution Interferometer Sounder (S-HIS) instrument is a cross track scanning Fourier-transform interferometer with 0.5 wavenumber resolution. It uses three detectors to cover the upwelling earth spectrum over the range from 3.3 to 17 microns. Vibration experienced during flight on aircraft platforms can cause a significant level of spectrally correlated noise in the calibrated spectra. To allow this interferometric noise to be removed by analysis, a wavefront tilt measurement system that monitors vibration induced optical tilts has been incorporated into the S-HIS instrument. This two-axis tilt measurement system records small changes in wavefront alignment during the data collection of both scene and blackbody interferograms. In general, both amplitude-modulation and sample-position errors can result from these tilts. Here we show that the modulation errors that dominate the interferometric noise in the S-HIS shortwave band can be significantly reduced by using the wavefront tilt measurements to model and remove the interferometric errors. The validation of our vibration induced tilt error model with blackbody data demonstrates a correction technique applicable to correcting all types of scene data.