SYSIPHE System: A state of the art airborne hyperspectral imaging system. Initial results from the first airborne campaign

SYSIPHE is an airborne hyperspectral imaging system and the result of a cooperation between France (Onera and DGA - Delegation Generale de l'Armement) and Norway (NEO and FFI (Forsvarets forskningsinstitutt)). It is a unique system by its spatial sampling of 0.5 m with a 500 m swath at a ground height of 2000 m combined with its wide spectral coverage from 0.4 micrometre to 11.5 microometre in the atmospheric transmission bands. Its infrared component, named SIELETERS, consists in two high etendue imaging static Fourier transform spectrometers, one for the midwave infrared and one for the longwave infrared. These two imaging spectrometers are closely similar in design, since both are made of a Michelson interferometer, a refractive imaging system, and a large infrared focal plane array (1016 x 440 pixels). Moreover, both are cryogenically cooled and mounted on their own stabilization platform which allows the line of sight to be controlled and recorded. These data are useful to reconstruct and to georeference the spectral image from the raw interferometric images.
The visible and shortwave infrared component, named Hyspex ODIN-1024, consists of two spectrographs for VNIR (Visible and Near InfraRed) and SWIR (Short Wave InfraRed) based on transmissive gratings. The latter share a common fore-optics and a common slit to ensure perfect registration between the VNIR and the SWIR images. The spectral resolution varies from 5 nm in the visible to 6 nm in the shortwave infrared.
In addition, the STAD, the postprocessing and archiving system, is developed to provide spectral reflectance and temperature products (SRT products) from calibrated georeferenced and inter-band registered spectral images at the sensor level acquired and pre-processed by SIELETERS and Hyspex ODIN-1024 systems.
SYSIPHE was flown for the first time in September 2013, over Cazaux, a French military airbase for experiments, and over Fauga-Mauzac in France where Onera has installed ground targets. A description of the experiment and some initial results are presented.