Development of autonomous in-fight navigation capability for a CubeSat mission is a challenging task, often ignored in favour of relying on a Global Navigation Satellite System (GNSS). However, the potential value in solving this problem becomes great for deep-space missions where such networks have limited coverage. This thesis presents a proof of concept for how autonomous navigation can be achieved using the star tracker already included in the design of the Hugin satellite, a 3U-CubeSat under development by Beyond Atlas AB in Stockholm. A navigation algorithm presented in existing literature was selected, processing optically derived angular measurements of distant celestial bodies in an Unscented Kalman Filter (UKF). The algorithm was then integrated with a custom-built orbit simulator to test the navigation in a fight environment. Results from these simulations demonstrate that this algorithm can be used to allow a satellite in geocentric orbit to consistently track its position using only optical measurements, and key parameters for tuning the navigation UKF have been identifed. Additionally, Hugin’s star tracker was tested in order to verify its capabilities and measure the accuracy and precision of angular measurements. Software for generating images containing stars and celestial bodies was custom-built and used for the tests. Results from these tests were inconclusive, as the star tracker was unable to identify stars displayed in the test images. The most probable cause for this inability was judged to be an insuffciently true-to-reality test environment, with several possible improvements identifed to increase the fidelity of future tests. Based on the results from the simulations this report concludes that autonomous navigation is possible on Hugin using the presented algorithm. Despite this, much work remains to be done with the major topics needing further investigation outlined in this report. / Utveckling av autonom satellitnavigation för CubeSats är en stor utmaning, och en som ofta väljs bort för att istället förlita sig på ett Global Navigation Satellite System (GNSS). Men tillgängligheten till sådana system är begränsad i yttre rymden, vilket gör förmågan att navigera autonomt mer värdefull. Detta examensarbete presenterar ett koncepttest för hur autonom navigering kan möjliggöras med hjälp av den stjärnkikare som är en del av satelliten Hugins design, en 3U CubeSat som utvecklas av Beyond Atlas AB i Stockholm. En navigationsalgoritm som presenterats i en kontemporär forskningsrapport har valts ut, vilken bearbetar optiska vinkelmätningar av avlägsna himlakroppar i ett Unscented Kalman Filter (UKF). Algoritmen har integrerats med en specialbyggd orbitalsimulator för att testa navigationens prestation i en rymdmiljö. Resultat från dessa simuleringar demonstrerar att med hjälp av denna algoritm kan en sattelit i geocentrisk omloppsbana konsekvent uppskatta sin position endast med hjälp av optiska mätningar. Nyckelparametrar för att ställa in navigationsfiltret har även identiferats. Utöver detta testades Hugins stjärnkikare för att verifera dess funktionalitet och mäta dess noggrannhet och precision. Mjukvara för att generera bilder innehållande stjärnor och himlakroppar specialbyggdes och användes för testerna. Testresultaten var ofullständiga, eftersom stjärnkikaren inte kunde identiferade stjärnor som visades i testbilderna. Det mest sannolika skälet till denna oförmåga bedömdes vara en ej tillräckligt verklighetstrogen testmiljö, med ett antal möjliga åtgärder identiferade. Utifrån simuleringsresultaten dras slutsaten att det är möjligt att utföra autonom navigation på Hugin med den framförda algoritmen. Trots detta återstår mycket arbete inom flera utvecklingsområden, varav de främsta beskrivs i denna rapport.

Idag lever cirka 365 000 personer med diabetes i Sverige. Mätningen av blodsocker kan upplevas som besvärlig och smärtsam med den apparatur som idag finns på marknaden. Vidare måste sjukvårdspersonal vara försiktiga vid hanteringen av teststickor pga. av den smittorisk som finns i kontakten med blod. Därför krävs en icke-invasiv mätmetod av blodglukos för att underlätta för diabetiker, eliminera risker för vårdpersonal och ge en möjlighet åt friska personer att ha koll på sitt blodglukosvärde på ett enkelt sätt.Följande examensarbete presenterar sjukdomen, dess följdsjukdomar och problematiken kring blodglukosmätningen. Arbetet har sin grund i en tidigare studie som gjorts kring optisk mätning av glukos, där resultatet visade på att glukos har en ljusabsorberande förmåga. Det påvisades genom att belysa en blandning av natriumkloridlösning och glukos, med infrarött ljus från en lysdiod. Det ljus som transmitterades bearbetades av en krets som bland annat bestod av en fotodetektor. Fotodetektorn genererade vidare en ström som i sin tur gjordes om till en utspänning som förstärktes.Under det arbete som redovisas i denna rapport testas en modifiering av kretsen för att undersöka om det går att upprätta, en korrelation mellan glukoskoncentrationen och utspänningen med hjälp av en transimpedansförstärkare kring fotodetektorn.De uppmätta spänningsvärdena redovisas i grafer och resultatet ger slutsatsen att kretsen ger en bättre korrelation mellan utspänning och glukoskoncentration, men en otillräcklig sådan vilket gör att tekniken inte kan användas kliniskt. / Today there are currently living around 365 000 people with diabetes in Sweden. Measuring of blood sugar can be experienced as painful and difficult with blood glucose monitoring devices found in the market. Using lancets and test strip makes direct contact with blood which increases the risk of infection. To reduce these risks and difficulties a non-invasive method is required. This method can even provide an opportunity for healthy individuals to monitor their blood glucose and prevent the disease.This thesis presents the disease, sequelae and the problem around blood glucose monitoring. The work is based on an earlier study about optic measurement of glucose. By illumine a solution of saline and glucose, with infrared-light from a LED, absorption is carried out by the glucose. The amount of transmitted light is detected and processed by a photodetector which generates a current that is converted to a voltage and amplified. This report examines a modification of the circuit used in the previous study to establish a correlation between the glucose concentration and the output voltage by adding a transimpedance amplifier around the photodetector.The results corroborate that the modification with the transimpedance gives a better correlation between the measured output voltage and glucose concentration. The measurements were compiled and plotted to compare which circuit gave a better correlation between the measured output voltage and glucose concentration. The study showed that the modification with transimpedance amplifier gives a better correlation, though it is not enough for clinical use.

<p>The paper and the graphics industries use two instruments with different optical geometry (d/0 and 45/0) to measure the quality of paper prints. The instruments have been reported to yield incompatible measurements and even rank samples differently in some cases, causing communication problems between these sectors of industry.A preliminary investigation concluded that the inter-instrument difference could be significantly influenced by external factors (background, calibration, heterogeneity of the medium). A simple methodology for eliminating these external factors and thereby minimizing the instrument differences has been derived. The measurements showed that, when the external factors are eliminated, and there is no fluorescence or gloss influence, the inter-instrument difference becomes small, depends on the instrument geometry, and varies systematically with the scattering, absorption, and transmittance properties of the sample.A detailed description of the impact of the geometry on the results has been presented regarding a large sample range. Simulations with the radiative transfer model DORT2002 showed that the instruments measurements follow the physical radiative transfer model except in cases of samples with extreme properties. The conclusion is that the physical explanation of the geometrical inter-instrument differences is based on the different degree of light permeation from the two geometries, which eventually results in a different degree of influence from near-surface bulk scattering. It was also shown that the d/0 instrument fulfils the assumptions of a diffuse field of reflected light from the medium only for samples that resemble the perfect diffuser but it yields an anisotropic field of reflected light when there is significant absorption or transmittance. In the latter case, the 45/0 proves to be less anisotropic than the d/0.In the process, the computational performance of the DORT2002 has been significantly improved. After the modification of the DORT2002 in order to include the 45/0 geometry, the Gauss-Newton optimization algorithm for the solution of the inverse problem was qualified as the most appropriate one, after testing different optimization methods for performance, stability and accuracy. Finally, a new homotopic initial-value algorithm for routine tasks (spectral calculations) was introduced, which resulted in a further three-fold speedup of the whole algorithm.The paper and the graphics industries use two instruments with different optical geometry (d/0 and 45/0) to measure the quality of paper prints. The instruments have been reported to yield incompatible measurements and even rank samples differently in some cases, causing communication problems between these sectors of industry.A preliminary investigation concluded that the inter-instrument difference could be significantly influenced by external factors (background, calibration, heterogeneity of the medium). A simple methodology for eliminating these external factors and thereby minimizing the instrument differences has been derived. The measurements showed that, when the external factors are eliminated, and there is no fluorescence or gloss influence, the inter-instrument difference becomes small, depends on the instrument geometry, and varies systematically with the scattering, absorption, and transmittance properties of the sample.A detailed description of the impact of the geometry on the results has been presented regarding a large sample range. Simulations with the radiative transfer model DORT2002 showed that the instruments measurements follow the physical radiative transfer model except in cases of samples with extreme properties. The conclusion is that the physical explanation of the geometrical inter-instrument differences is based on the different degree of light permeation from the two geometries, which eventually results in a different degree of influence from near-surface bulk scattering. It was also shown that the d/0 instrument fulfils the assumptions of a diffuse field of reflected light from the medium only for samples that resemble the perfect diffuser but it yields an anisotropic field of reflected light when there is significant absorption or transmittance. In the latter case, the 45/0 proves to be less anisotropic than the d/0.In the process, the computational performance of the DORT2002 has been significantly improved. After the modification of the DORT2002 in order to include the 45/0 geometry, the Gauss-Newton optimization algorithm for the solution of the inverse problem was qualified as the most appropriate one, after testing different optimization methods for performance, stability and accuracy. Finally, a new homotopic initial-value algorithm for routine tasks (spectral calculations) was introduced, which resulted in a further three-fold speedup of the whole algorithm.</p> / QC 20100707 / PaperOpt, Paper Optics and Colour

Optiska system används för att utvärdera om tuber är hela och rena innan de fylls med sitt innehåll. Bilder tas lodrätt ner i tuben och behandlas i kameran som sedan skickar en signal till maskinen. Tagna bilder behandlas med olika filter innan utvärdering sker. Om filter appliceras i algoritmen kan säkerheten i utfallet höjas men på bekostnad av tid.

In the residual waste bags in the municipality of Halmstad, only 28% of the waste was sorted correctly according to the pick analysis from spring 2018. In the municipality's new waste plan from 2019, one of the objectives is that this number should be 75% in 2025. Our aim with this study is to provide a basis on what it takes to get more inhabitants in Halmstad to sort their waste correctly. We hope that our results will be useful for Halmstad’s municipality in their work to achieve objective 2.1 in the new waste plan. Our main study question is: What would be required to get residents in Halmstad to sort their waste to a greater degree? To get answers to these questions, we conducted telephone and physical interviews with residents of the Vallås district in Halmstad. Our results from the interviews show that women recycle more than men, those who live in detached house/townhouses and co-operative apartment recycle more than those who live in rented apartment, age group 18-35 recycled the least and the ones over 65 years recycled the most. The main reason why people recycle is for the sake of the environment. Of those who did not recycle at least one fraction, most said that it is either because they could not manage to or that they have too far to a recycling station. According to our study, there are clear differences between different groups of inhabitants and their recycling habits, which means that you have to insert different actions for different groups. Some appropriate actions could be to inform about source separation more often on tv and in newspapers and to provide information in more languages. / I påsarna för restavfall i Halmstads kommun var det endast 28% av avfallet som var rätt sorterat enligt plockanalyser från 2018. I kommunens nya avfallsplan från 2019 är ett av målen att den siffran ska ligga på 75% till år 2025. Vårt syfte med denna studie är att ta fram ett underlag om vad som kan få fler invånare att källsortera, som Halmstads kommun kan jobba vidare med för att kunna uppnå mål 2.1 i den nya avfallsplanen. Vår huvudfrågeställning är: vad skulle krävas för att få invånare i Halmstad att sortera sitt avfall i högre grad? De tre underfrågeställningarna är följande: Finns skillnader mellan olika grupper av invånare gällande hur de källsorterar sitt avfall? Av vilken anledning källsorterar de som redan gör det idag och av vilken anledning källsorterar inte de som inte gör det idag? Hur bra kunskap har invånarna om källsortering? För att få svar på dessa frågeställningar genomfördes telefon- och fysiska intervjuer med invånare i Vallås; en stadsdel med en mångfald av människor som kan representera hela Halmstad. Till dessa använde vi oss av en enkät med 23 frågor om personerna och deras källsorteringsvanor. Enkäten innehöll både kvalitativa och kvantitativa frågor för att få så bra svar som möjligt. Majoriteten av de fysiska mötena ägde rum på ICA Supermarket i Vallås och personerna valdes ut slumpmässigt. Svaren sammanställdes i Excel och det var där diagrammen till resultatet framställdes. Våra resultat från intervjuerna visar att kvinnor källsorterar mer än män, de som bor i villa/radhus och bostadsrätt mer än de som bor i hyresrätt, åldersgruppen 18–35 källsorterar minst och de över 65 år mest. Den främsta anledningen till att folk källsorterar är för miljöns skull och av de som inte källsorterar samtliga fraktioner uppgav de flesta att det antingen beror på att de inte orkar eller att de har för långt till en återvinningsstation. Majoriteten av de tillfrågade tyckte att de har fått tillräckligt med information från kommunen för att kunna sortera rätt, men knappt hälften kände till att det finns lag på att man ska källsortera och knappt en tredjedel hade hört talas om den kommunala avfallsplanen. Enligt vår studie finns det tydliga skillnader mellan invånares källsorteringsvanor vilket betyder att olika åtgärder måste sättas in för olika grupper. Till exempel skulle det behövas mer information om källsortering på radio, tv och nyheter och även information på fler språk till de som inte kan svenska. Vår förhoppning är att Halmstads kommun ska få användning av vårt resultat i deras arbete för att få fler invånare att sortera sitt avfall rätt.

<p>GaN quantum dots grown by molecular beam epitaxy are examined by micro-photoluminescence. The exciton and biexciton emission are identified successfully by power-dependence measurement. With two different samples, it can be deduced that the linewidth of the peaks is narrower in the thicker deposited layer of GaN. The size of the GaN quantum dots is responsible for the binding energy of biexciton (E^b_XX); E^b_XXdecreases with increasing size of GaN quantum dots. Under polarization studies, polar plot shows that emission is strongly linear polarized. In particular, the orientation of polarization vector is not related to any specific crystallography orientation. The polarization splitting of fine-structure is not able to resolve due to limited resolution of the system. The emission peaks can be detected up to 80 K. The curves of transition energy with respect to temperature are S-shaped. Strain effect and screening of electric field account for  blueshift of transition energy, whereas Varshni equation stands for redshifting. Both blueshifting and redshifting are compensated at temperature ranging from 4 K to 40 K.</p>

<p>Complex surface structures in nature often have remarkable optical properties. By understanding the origin of these properties, such structures may be utilized in metamaterials, giving possibilities to create materials with new specific optical properties. To simplify the optical analysis of these naturally developed surface structures there is a need to assist data analysis and analytical calculations with numerical calculations.</p><p>In this work an application tool for numerical calculations of optical properties of surface structures, such as reflectances and ellipsometric angles, has been developed based on finite element methods (FEM). The data obtained from the application tool has been verified by comparison to analytical expressions in a thorough way, starting with reflection from the simplest of interfaces stepwise increasing the complexity of the surfaces.</p><p>The application tool were developed within the electromagnetic module of Comsol Multiphysics and used the script language to perform post-process calculations on the obtained electromagnetic fields. The data obtained from this application tool are given in such way that easily allows for comparison with data received from spectroscopic ellipsometry measurements.</p>

This thesis explores the use of engineered nonlinear crystals from the KTiOPO4 (KTP) family as the gain material in optical parametric amplifiers (OPAs), with the aim to achieve more knowledge about the benefits and limitations of these devices. The work aims further at extending the possible applications of OPAs by constructing and investigating several efficient and well performing amplifiers. An OPA consists of a strong pump source, which transfers its energy to a weak seed beam while propagating through a nonlinear crystal. The crystals employed in this work are members of the KTP family, which are attractive due to their large nonlinear coefficients, high resistance to damage and wide transparency range. The flexibility of OPAs with respect to different wavelength regions and pulse regimes was examined by employing various dissimilar seed and pump sources. The possibility to adapt an OPA to a specific pump and seed wavelength and achieve efficient energy conversion between the beams, originates from quasi-phasematching, which is achieved in periodically poled (PP) nonlinear crystals. Quasi-phasematched samples can be obtained by changing the position of certain atoms in a ferroelectric crystal and thereby reversing the spontaneous polarisation. In this thesis several material properties of PP crystals from the KTP family were examined. The wavelength and temperature dispersion of the refractive index were determined for PP RbTiOPO4, which is essential for future use of this material. Another experiment helped to increase the insight into the volumes close to domain walls in PP crystals Further, several OPAs were built and their ability to efficiently amplify the seed beam without changing its spectral or spatial properties was studied. Small signal gains of up to 55 dB and conversion efficiencies of more than 35 % were achieved for single pass arrangements employing 8 mm long PPKTP crystals. Apart from constructing three setups, which generated powerful nanosecond, picosecond and femtosecond pulses, the possibility to amplify broadband signals was investigated. An increase of the OPA bandwidth by a factor of approximately three was achieved in a noncollinear configuration. / QC 20101013

GaN quantum dots grown by molecular beam epitaxy are examined by micro-photoluminescence. The exciton and biexciton emission are identified successfully by power-dependence measurement. With two different samples, it can be deduced that the linewidth of the peaks is narrower in the thicker deposited layer of GaN. The size of the GaN quantum dots is responsible for the binding energy of biexciton (EbXX); EbXX decreases with increasing size of GaN quantum dots. Under polarization studies, polar plot shows that emission is strongly linear polarized. In particular, the orientation of polarization vector is not related to any specific crystallography orientation. The polarization splitting of fine-structure is not able to resolve due to limited resolution of the system. The emission peaks can be detected up to 80 K. The curves of transition energy with respect to temperature are S-shaped. Strain effect and screening of electric field account for  blueshift of transition energy, whereas Varshni equation stands for redshifting. Both blueshifting and redshifting are compensated at temperature ranging from 4 K to 40 K.

Complex surface structures in nature often have remarkable optical properties. By understanding the origin of these properties, such structures may be utilized in metamaterials, giving possibilities to create materials with new specific optical properties. To simplify the optical analysis of these naturally developed surface structures there is a need to assist data analysis and analytical calculations with numerical calculations. In this work an application tool for numerical calculations of optical properties of surface structures, such as reflectances and ellipsometric angles, has been developed based on finite element methods (FEM). The data obtained from the application tool has been verified by comparison to analytical expressions in a thorough way, starting with reflection from the simplest of interfaces stepwise increasing the complexity of the surfaces. The application tool were developed within the electromagnetic module of Comsol Multiphysics and used the script language to perform post-process calculations on the obtained electromagnetic fields. The data obtained from this application tool are given in such way that easily allows for comparison with data received from spectroscopic ellipsometry measurements.