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In recent years TNO has investigated and developed different innovative opto-mechanical designs to realize advanced spectrometers for space applications in a more compact and cost-effective manner. This offers multiple advantages: a compact instrument can be flown on a much smaller platform or as add-on on a larger platform; a low-cost instrument opens up the possibility to fly multiple instruments in a satellite constellation, improving both global coverage and temporal sampling (e.g. multiple overpasses per day to study diurnal processes); in this way a constellation of low-cost instruments may provide added value to the larger scientific and operational satellite missions (e.g. the Copernicus Sentinel missions); a small, lightweight spectrometer can easily be mounted on a small aircraft or high-altitude UAV (offering high spatial resolution). Moreover, a low-cost instrument may allow us to break through the ‘cost spiral’: lower cost will allow us to take more technical risk and thus be more innovative. This will lead to a much faster development cycle than customary for current Earth-observation instruments. Finally, the TNO designs offer flexibility to tune the performance (spectral range, spectral resolution) of the spectrometer to a specific application (like air quality, climate, water quality, etc ). Thus, based on the same basic system design, these instruments offers a wide range of applications to a variety of clients, both inside and outside the scientific community using a quasi-recurrent instrument (reducing the development cost for each instrument). In this paper the most mature design of a hyperspectral imaging spectrometer (named ‘Spectrolite’) is used to illustrated this innovative approach. For this purpose chapter II will introduce the Spectrolite concept, design philosophy and breadboard (BB). Chapter III will discuss how the Breadboard was transformed into an airborne instrument (for a test flight over Berlin as part of AROMAPEX [7]) in the time frame of only a month. The (reduced) Level 0-1B data processor and corresponding characterization measurements (performed in only 5 days) are presented in Chapter IV, followed by achieved NO2 retrieval results from the airborne test flight over Berlin in chapter V. Finally chapter VI will provide a conclusion and present the next steps for Spectrolite. |
