Feature-specific on-board technology for airborne spectral imaging: Master's thesis

This thesis describes the feasibility of a novel concept utilising on-board optical data processing for airborne spectral imaging. The main goal was to characterise the laboratory version of the instrument with the aid of simulations and measurements. Compared with traditional imaging spectrometers, this instrument radically reduces data processing time and data input, thus enabling real-time recognition and analysis. The instrument can be used in applications where the algorithm is known beforehand. A mathematical model was developed for the instrument and its performance was evaluated in order to compare different concept variations. All components were measured and characterised individually, and the results were used in the simulations. Performance was then analysed by means of radiometric throughput and spatial and spectral resolutions. The simulations were performed at wavelengths of 450 nm to 900 nm. The throughput was found to be between 1% and 4.5%. The set-up was characterised using a neon lamp and slit at a distance of two and a half metres. The measurements were performed on-axis at wavelengths between 600 nm and 680 nm. There was good correlation between the simulations and measurements. The spectral resolution was found to be 3 nm. For a modulation of 20%, the spatial frequency on the image sensor was 24 lp/mm. The results show that the concept is suitable for feature-specific airborne spectral imaging thanks to its good spectral resolution and reasonable radiometric throughput and spatial resolution.