Laurent Rousset-Rouviere

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, result of a cooperation between France (Onera and DGA) and Norway (NEO and FFI). It is a unique system by its spatial sampling -0.5m with a 500m swath at a ground height of 2000m- combined with its wide spectral coverage -from 0.4μm to 11.5μm in the atmospheric transmission bands. Its infrared component, named SIELETERS, consists in two high étendue 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 IRFPA (1016x440 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 and SWIR based on transmissive gratings. These 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 5nm in the visible to 6nm in the shortwave infrared. In addition, the STAD, the post processing 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: the new-generation airborne remote sensing system

The SYSIPHE system is the state of the art airborne hyperspectral imaging system developed in European cooperation. With a unique wide spectral range and a fine spatial resolution, its aim is to validate and quantify the information potential of hyperspectral imaging in military, security and environment applications. The first section of the paper recalls the objectives of the project. The second one describes the sensors, their implementation onboard the platform and the data processing chain. The last section gives illustrations on the work in progress.

SYSIPHE: focus on SIELETERS, the medium and longwave infrared spectral imaging instrument

Sysiphe is an airborne hyperspectral imaging system, result of a cooperation between France (Onera and DGA) and Norway (NEO and FFI). It is a unique system by its spatial sampling -0.5m with a 500m swath at a ground height of 2000m- combined with its wide spectral coverage -from 0.4μm to 11.5μm in the atmospheric transmission bands. Its infrared component, named Sieleters, consists in two high étendue imaging static Fourier transform spectrometers, one for the midwave infrared and one for the longwave infrared. These two imaging spectrometers have very close design, since both are made of a Michelson interferometer, a refractive imaging system, and a large IRFPA (1016x440 pixels). Moreover, both are cryogenic and mounted on their own stabilization platform which allows at once to actively control and independently measure the line of sigh. These data are useful to reconstruct and to georeference the spectral image from the raw interferometric images. Sysiphe first flight occurred in September, 2013.

SETHI and SYSIPHE: the two new-generation airborne remote sensing systems

This paper presents the new-generation airborne remote sensing systems SETHI and SYSIPHE, developed by ONERA, the French Aerospace Lab, and dedicated to environmental, scientific and security applications. Today, many scientists from climatologists to agronomists, need specific types of information that cannot be provided in full by conventional observation systems to solve complex problems. Onera offers them a solution to use the huge potential of multispectral and hybrid radar/optronics data. The SETHI remote sensing system is dedicated to provide a unique combination of radar and optronics images, including polarimetric SAR, visible and short wave infrared, multispectral images, ... This all-in-one system is operational from 2008 in radar configuration, its optronics capability becomes operational gradually. The SYSIPHE system is the state of the art airborne hyperspectral imaging system developed in European cooperation. With a unique wide spectral range and a fine spatial resolution, its aim is to validate and quantify the information potential of hyperspectral imaging in military, security and environment applications. The first section of the paper introduces the objectives of the projects and their general architecture. The second one describes the sensors, their implementation onboard the platforms, the data processing chain and gives an overview of the projects planning. The third section presents some significant results.

System design of an airborne infrared measurement system

Onera has designed and developed an scientific airborne infrared measurement system. This system is constituted of a supervisor computer and two scientific instruments (a cryogenic IR multiband camera and a cryogenic IR spectro-radiometer). This article presents the different elements of the system and focuses on the design of the cryogenic IR camera. The IR camera design involves instrument control, data acquisition, IRIG time stamping, target acquisition and tracking. This article highlights also the communication design using two Ethernet networks linking the elements of the experimental measurement chain.

NAOS computer-aided control: an optimized and astronomer-oriented way of controlling large adaptive optics systems

Adaptive Optics as a new tool for astronomical observation has proved a powerful means of investigation in high angular resolution programs. However, in spite of the complexity of the components involved (wavefront sensor, real-time computer), its use must be made as simple as possible in order to make it accessible to the largest audience of observers, and to answer the more demanding needs of modern observatories such as queue scheduling, service observing or remote observing. The Computer Aided Control developed for the Nasmyth Adaptive Optics System of the Very Large Telescope, will provide the astronomer with an extensive support, from the preparation of optimized observations to the automated operation of the instrument at the telescope either for hardware control, real time computing, or even preventive maintenance.

Study of infrared optical payloads to be integrated in a nanosat

Nanosats or CubeSats are emerging technologies corresponding to miniaturized satellites with a wet mass between 1 and 10kg. In this study, we explored the possibility of doing earth observation in the longwave infrared. The challenge is to integrate the longest focal length as possible in a 2U volume dedicated to the optical payload. Another challenge is to use a low cost, lightweight and low power consumption microbolometer which requires high apertures optics. For these volumes, there is a competition between refractive designs, often more compact when having high apertures, and reflective designs, having a lower mass and being easily athermalized. The choice is not obvious and we studied a telephoto refractive design and an off-axis Three Mirror Anastigmat (TMA) reflective design. The key technology for the telephoto design is the use of chalcogenide glasses whereas the key technology for the TMA is the use of freeform surfaces.

Results from the first flight campaign of Sieleters, an airborne infrared Imaging Fourier Transform Spectrometer

Sieleters is an airborne MWIR and LWIR imaging Fourier Transform Spectrometer developed at Onera. The first flight campaign was led at the end of 2013. Experimental results are presented, including a comparison with simulated data.

SYSIPHE, airborne hyperspectral system: Focus on the SIELETERS thermal hyperspectral imaging instrument

The SYSIPHE system is the state of the art airborne hyperspectral imaging system developed in European cooperation. With a unique wide spectral range and a fine spatial resolution, its aim is to validate and quantify the information potential of hyperspectral imaging in military, security and environment applications. The first section of the paper recalls the architecture of the project. The second one describes the SIELETERS sensors, their implementation onboard the platform and the data processing chain. The last section gives illustrations on the work in progress.

Sieleters, an airbone Imaging Static Fourier Transform Spectrometer: design and preliminary laboratory results

Sieleters is an airborne hyperspectral imager, composed of two cryogenic instruments (MWIR and LWIR), both based on a static interferometer. Its first flight is expected for June, 2013. We present design details and preliminary laboratory results.