The Geosynchronous Imaging Fourier Transform Spectrometer GIFTS): Noise Performance

摘要

The NASA New Millennium Program (NMP) Geosynchronous Imaging Fourier Transform Spectrometer (GIFTS) instrument was designed to demonstrate new and emerging technologies and provide immense improvements in satellite based remote sensing of the atmosphere from a geostationary orbit [1]. Combining a Fourier Transform Spectrometer (FTS) and Large Area Focal Plane Arrays, GIFTS measures incident infrared radiance with an extraordinary combination of spectral, temporal, and spatial resolution and coverage. Thermal vacuum testing of the GIFTS Engineering Development Unit (EDU) was performed at the Space Dynamics Laboratory and completed in May 2006 [2,3]. The GIFTS noise performance measured during EDU thermal vacuum testing indicates that threshold performance has been realized, and that goal performance (or better) has been achieved over much of both the Longwave Infrared (LWIR) and Short/Midwave Infrared (SMWIR) detector bands. An organizational structure for the division of the noise sources and effects for the GIFTS instrument is presented. To comprehensively characterize and predict the effects of measurement noise on expected instrument performance, the noise sources are categorically divided and a method of combining the independent effects is defined. Within this architecture, the total noise is principally decomposed into spectrally correlated noise and random (spectrally uncorrelated) noise. The characterization of the spectrally correlated noise sources specified within the structure is presented in detail.