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Forward Looking Infrared (FUR) systems are commonly used in military applications for the purposes of detecting and recognising moving or stationary objects. FUR imagery is particularly effective in low visibility environments and can provide additional information which would not be available in visible band images. The disadvantages of FUR imagery are that it tends to be extremely noisy, low contrast, and cluttered due to manufacturing limitations and environmental constraints. Contemporary research has mainly focused on applying detection and recognition techniques directly to FUR image sequences. However, compared with visible band images, FUR imagery has much poorer quality which results in greater difficulty in detecting and recognising objects. This thesis describes the development of techniques to improve the quality of FUR imagery prior to performing detection and recognition, with the aim of improving object detection and recognition performance. Super resolution and image mosaicing techniques have been employed for high-resolution assessment of individual areas and high-level situational awareness of large areas respectively. Both super. resolution and image mosaicing rely heavily on accurate image registration hence an image registration system with sub-pixel accuracy has been developed especially for FUR imagery. This image registration technique aligns imagery efficiently and accurately in spite of the inherent limitations of FUR images. Then, a robust and efficient super resolution method has been adopted to enhance the image resolution and a mosaicing method based on the super resolution method used to enlarge the field of view of the image. In addition, cloud effects have been considered and a segmentation scheme developed to deal with cloud cover on FUR imagery.

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A number of novel doped glasses have been studied for their potential as infrared amplifier materials. Optical amplifiers which operate outside of the C-band are likely to form part of future optical telecoms systems. This work is focused on transition metal and rare earth-doped materials which could provide gain in the telecoms S-band. Nickel and Vanadium-doped gallium lanthanum sulphide (GLS) glasses were identified as possible new amplifier materials. Emission was observed at 1200nm from Ni-doped GLS and at 1400nm for V-doped GLS. The FWHM of the emission from V-doped GLS was 450 nm, making it particularly attractive for a broadband optical amplifier. Low temperature emission spectra from V-doped GLS suggest that it is not affected by nonradiative decay to the same extent as Cr-doped GLS. Thulium and erbium-doped tin silicate glass-ceramics produced by the sol-gel method were studied for as potential amplifier materials. The addition of tin oxide to these glasses makes them photosensitive and is shown in this work to increase fluorescence lifetimes. However, the addition of >5% SnO2 causes increased infrared absorption which would outweigh advantages gained by the increased lifetime. Thulium-doped tin silicate glass-ceramics were investigated for the first time, and show a broad fluorescence band at 1470 nm with a FWHM of ~120 nm. The maximum lifetime of the 3F4 level was 37 μs, which is higher than in Tm-doped silica. Y2O3-Al2O3-SiO2 (YAS) glass was investigated as a low phonon silicate host for a thulium-doped fibre amplifier. Raman and FTIR measurements showed that the maximum phonon energy can be reduced by increasing the yttria:alumina ratio and decreasing the silica content. This was confirmed by emission lifetime measurements of the 3F4 level, which showed an increase in lifetime of 20% over the range studied. A Tm-doped YAS fibre was successfully drawn from a glass of the composition 17.4% Y2O3, 22.5% Al2O3 and 60% SiO2. 7.5 m of continuous unclad fibre was fabricated with a diameter of 150-350 μm at a temperature of 1150°C. The minimum loss in the fibre was measured to be 3.6 dB/m at 1360 nm. This material is shown to have good potential for use in S-band fibre amplification