Natural Scene Statistics (NSS) provide powerful perceptually relevant tools that have been successfully used for image quality analysis of visible light images. NSS capture statistical regularities that arise in the physical world and thus are relevant to Long Wave Infrared (LWIR) images. LWIR images are similar to visible light images and mainly differ by the wavelengths captured by the sensors. The distortions unique to LWIR are of particular interest to current researchers. We analyze a few common LWIR distortions and how they relate to NSS models. Humans are the most important factor for assessing distortion and quality in IR images, which are often used in perceptual tasks. Therefore, predicting human performance when a task involving LWIR images needs to be performed can be critical to improving task efficacy. The National Institute for Standards and Technology (NIST) characterizes human Targeting Task Performance (TTP) by asking firefighters to identify the locations of fire hazards in LWIR images under distorted conditions. We find that task performance can be predicted using NSS features. We also report the results of a human study. We analyzed the NSS of LWIR images under pristine and distorted conditions using four databases of LWIR images. Each database was captured with a different camera allowing us to better evaluate the statistics of LWIR images independent of camera model. We find that models of NSS are also effective for measuring distortions in the presence of other independent distortions. / text

In this thesis, algorithms for image registration and segmentation are developed to locate and identify DU penetrators and associated metal projectile debris on or near the surface at the US DoD firing ranges and proving grounds. The proposed registration algorithm supports fusing the LWIR and visible images. Control points are indentified by area-base detection and followed by eliminating outliers. Associated with bilinear interpolation, the gravity centers of control points are used to estimate the transformation parameters. The segmentation with a statistical detector is developed to improve the fusion result. The power spectrum density is invoked to extract and identify the image properties, and the probability of each pixel classified as target further the decision. The final result is consistent with the true vision and carries distinguished target information. The combination of registration and segmentation approaches can effectively orientate and investigate the target area.

Quantum Well Infrared Photodetectors (QWIPs) have the advantages of excellent uniformity and mature material properties. Thanks to these properties, large format and low cost QWIP focal plane arrays (FPAs) can be fabricated. The standard material system used for QWIP FPAs is AlGaAs/GaAs in the long wavelength infrared (LWIR) band. AlGaAs/GaAs material system has some disadvantages such as low quantum and conversion efficiencies under high frame rate and/or low background conditions. These limitations of the standard material system give rise to research on alternative material systems for QWIPs. InP/InGaAs material system is an alternative to AlGaAs/GaAs for LWIR QWIPs. This thesis focuses on the development of InP/InGaAs QWIP FPAs. A large format (640x512) LWIR QWIP FPA constructed with strained InP/InGaAs system is demonstrated with high quantum and conversion efficiencies. The FPA fabricated with the 40-well epilayer structure yielded a peak quantum efficiency as high as 20% with a broad spectral response (15%). The responsivity peak and the cut-off wavelengths of the FPA are 8.5 and ~9 um, respectively. The peak responsivity of the FPA pixels is larger than 1 A/W with a conversion efficiency as high as ~17 % in the bias region where the detectivity is reasonably high. The FPA provides a background limited performance (BLIP) temperature higher than 65 K (f/1.5) and satisfies the requirements of most low integration time/low background applications. Noise equivalent temperature difference (NETD) of the FPA is as low as 25 mK with integration times as short as 2 ms (f/1.5, 68 K).

The poaching of rhinoceros has increased dramatically the last few years andthe park rangers are often helpless against the militarised poachers. LinköpingUniversity is running several projects with the goal to aid the park rangers intheir work.This master thesis was produced at CybAero AB, which builds Remotely PilotedAircraft System (RPAS). With their helicopters, high end cameras with a rangesufficient to cover the whole area can be flown over the parks.The aim of this thesis is to investigate different methods to automatically findrhinos and humans, using airborne cameras. The system uses two cameras, onecolour camera and one thermal camera. The latter is used to find interestingobjects which are then extracted in the colour image. The object is then classifiedas either rhino, human or other. Several methods for classification have beenevaluated.The results show that classifying solely on the thermal image gives nearly as highaccuracy as classifying only in combination with the colour image. This enablesthe system to be used in dusk and dawn or in bad light conditions. This is animportant factor since most poaching occurs at dusk or dawn. As a conclusion asystem capable of running on low performance hardware and placeable on boardthe aircraft is presented. / Tjuvjakten av noshörningar har ökat drastiskt de senaste åren och parkvakternastår ofta handfallna mot militariserade tjuvjägare. Linköpings Universitet arbetarpå flera projekt som på olika sätt ska vara ett stöd för parkvakterna i deras arbete.Examensarbetet genomfördes på CybAero AB som jobbar med att bygga fjärrstyrdahelikoptrar, så kallade RPAS (Remotely Piloted Aircraft System). Med derassystem kan man bära högkvalitativa kameror och ha stor räckvidd så hela parkenkan övervakas.Det här examensarbetet syftar på att undersöka olika metoder för att från luftburnakameror kunna ge information om vad som pågår i parken. System bygger påatt man har två kameror, en vanlig färgkamera och en värmekamera. Värmekamerananvänds för att hitta intressanta objekt som sedan plockas ut ur färgbilden.Objektet klassificeras sedan som antingen noshörningar, människor eller annat.Flertalet metoder har utvärderas utefter deras förmåga att klassificera objektenkorrekt.Det visade sig att man kan få väldigt bra resultat när man klassificerar endastpå värmebilden vilket ger systemet möjlighet att operera även när det är skymningeller mörkt ute. Det är en väldigt viktig del då de flesta djuren skjuts vidantingen gryning eller skymning. Som slutsats i rapporten presenteras ett förslagpå system som kan köras på lågpresterande hårdvara för att kunna köras direkt iluften.

Infrared cameras can directly measure the apparent temperature of objects, providing thermal imaging. However, the raw output from most infrared cameras suffers from a strong, often limiting noise source called nonuniformity. Manufacturing imperfections in infrared focal planes lead to high pixel-to-pixel sensitivity to electronic bias, focal plane temperature, and other effects. In turn, different pixels within the focal plane array give a drastically different electronic response to the same irradiance. The resulting imagery can only provide useful thermal imaging after a nonuniformity calibration has been performed. Traditionally, these calibrations are performed by momentarily blocking the field of view with a flat temperature plate or blackbody cavity. However because the pattern is a coupling of manufactured sensitivities with operational variations, periodic recalibration is required, sometimes on the order of tens of seconds. A class of computational methods called Scene-Based Nonuniformity Correction (SBNUC) has been researched for over 20 years where the nonuniformity calibration is estimated in digital processing by analysis of the video stream in the presence of camera motion. The most sophisticated SBNUC methods can completely and robustly eliminate the high-spatial frequency component of nonuniformity with only an initial reference calibration or potentially no physical calibration. I will demonstrate a novel algorithm that advances these SBNUC techniques to support all spatial frequencies of nonuniformity correction. Long-wave infrared microgrid polarimeters are a class of camera that incorporate a microscale per-pixel wire-grid polarizer directly affixed to each pixel of the focal plane. These cameras have the capability of simultaneously measuring thermal imagery and polarization in a robust integrated package with no moving parts. I will describe the necessary adaptations of my SBNUC method to operate on this class of sensor as well as demonstrate SBNUC performance in LWIR polarimetry video collected on the UA mall.

Efficient absorption of light is required for a large number of applications such as thermo-photovoltaics,thermal imaging, bio-sensing, thermal emitters, astronomy, and stealth technology. Strong light absorbers found in nature with high intrinsic losses such as carbon black, metal-black, and carbon nano-tubes etc. are bulky, not design-tunable and are hard to pattern for micro- and nano- devices. We developed thin-film, high performance absorbers in the visible, near-, mid-, long-wave - and far-IR region based on a 3 layer metal-dielectric-metal (MDM) structure. We fabricated a 3-layerMDMabsorber with large band-widths in the visible and near IR spectral range without any lithographic patterning. This was the first demonstration in the optical range of the Salisbury Screen, which was originally invented for radar absorption. A Fabry-Perot cavity model depending on the thickness of the dielectric, but also the effective permittivity of the semi-transparent top metal gives calculated spectra that agree well with experiment. Secondly, we fabricated long-wave IR and far-IR MDM absorbers comprising surface patterns of periodic metal squares on the dielectric layer. Strong absorption in multiple bands were obtained, and these depended weakly on polarization and angle of incidence. Though such absorbers had been extensively studied by electrodynamic simulations and experiment in the visible to far- R regions, there existed no analytic model that could accurately predict the wavelengths of the multiple resonances. We developed a theoretical model for these absorbers based on standingwave resonances, which accurately predicts resonance wavelengths for experiment and simulation for the first time. Unlike metamaterial theories our model does not depend on the periodicity of the squares but only on their lateral dimension and the thickness of the dielectric. This feature is confirmed by synchrotron-based IR spectral imaging microscopy of single isolated squares.

In der vorliegenden Arbeit werden die Möglichkeiten einer Nutzung thermal-infraroter Wellenlängen zur fernerkundlichen Erfassung/Quantifizierung von Bodenparametern vorgestellt. Die Studie basiert auf Bodenproben des Untersuchungsgebietes Mullewa, welches sich in einer semiariden Agrarregion im West-Australischen Weizengürtel befindet. Im Mittelpunkt der Arbeit steht die Bewertung des langwelligen Infrarots (LWIR), innerhalb des atmosphärischen Fensters zwischen 8 und 14 Mikrometer, bezüglich seines spektralen Potentials für die quantitative Ableitung des Ton- und Sandgehaltes sowie des Gehaltes an organischem Kohlenstoff (SOC). Zur Abschätzung der Effizienz wurden die Ergebnisse des LWIR einer Quantifizierung aus dem herkömmlich gebrauchten solar-reflektiven Wellenlängenbereichs zwischen 0,4 und 2,5 Mikrometer (VNIR-SWIR) gegenübergestellt. Mit verschiedenen Methoden der Laborspektroskopie wurden Bodenproben aus dem Untersuchungsgebiet im thermalen (Emissions-FTIR-Spektroskopie und direktional-hemisphärische Reflexions- (DHR) Spektroskopie)und im solar-reflektiven (Diffuse Reflexions-Spektroskopie) Wellenlängenbereich eingemessen und anschließend auf ihren Informationsgehalt hin untersucht. Die quantitative Modellierung der pedologischen Parameter aus den gemessenen spektralen Signaturen wurde mithilfe einer multivariaten Regressionsanalyse (Partial Least Squares Regression – PLSR) realisiert. Diese Grundlagenstudie konnte zeigen, dass die spektralen Voraussetzungen im LWIR für ein mögliches Monitoring der Bodenparameter mit thermalen Fernerkundungsdaten gegeben sind. Die Arbeit demonstriert darüber hinaus, dass für die Erfassung/Quantifizierung der Textur-Parameter (Sand- und Tongehalt) der relevante spektrale Informationsgehalt im LWIR deutlich höher ist als im VNIR-SWIR. / This study embraces the feasibility of using the thermal infrared wavelength region for future remote sensing applications to detect/quantify soil parameters. The research is based on soil samples from the semiarid agricultural area of Mullewa, located within the wheat belt of Western Australia. The main focus of this study is to assess the potential of the longwave infrared (LWIR), within the atmospheric window between 8 and 14 micrometer, to predict the content of sand, clay and organic carbon (SOC) in soils. The results are compared with predictions made with the traditionally used solar-reflective wavelength region (visible, VIS: 0.4 - 0.7 micrometer; near infrared, NIR: 0.7 - 1.1 micrometer; shortwave infrared, SWIR: 1.1 - 2.5 micrometer). Using laboratory spectroscopy, the Mullewa soil samples were measured, both in the thermal infrared (emission FTIR spectroscopy and directional hemispherical reflection (DHR) spectroscopy) and in the solar-reflective (diffuse reflection spectroscopy) wavelength region. This data was analyzed to determine the relevant content of information for the soil parameters. Multivariate regression analyses (partial least squares regression - PLSR) were used to quantitatively model the soil parameters from the spectral signatures. This basic research demonstrated that the spectral requirements in the LWIR are met for monitoring these soil parameters with thermal remote sensing instruments. Furthermore the study found that the relevant spectral information for the detection/quantification of the sand- and the clay content (textural parameters) is explicitly higher in the LWIR than in the VNIR-SWIR.

Quantum Well Infrared Photodetectors (QWIPs) are strong competitors to other detector technologies for future third generation thermal imagers. QWIPs have inherent advantages of mature III-V material system and well settled fabrication technology, as well as narrow band photo-response which is an important property facilitating the development of dual-band imagers with low crosstalk. This thesis focuses on the development of long/mid wavelength dual band QWIP focal plane arrays (FPAs) based on the AlGaAs/GaAs material system. Apart from traditional single band QWIPs, the dual-band operation is achieved by proper design of a bias tunable quantum well structure which has two responsivity peaks at 4.8 and 8.4 um for midwave infrared (MWIR) and longwave infrared (LWIR) atmospheric windows, respectively. The fabricated large format (640x512) FPA has MWIR and LWIR cut-off wavelengths of 5.1 and 8.9 um, and it provides noise equivalent temperature differences (NETDs) of ~ 20 and 32 mK (f/1.5 at 65 K) in these bands, respectively. The employed bias tuning approach for the dual-band operation requires the same fabrication steps established for single band QWIP FPAs, which is an important advantage of the selected method resulting in high-yield, high-uniformity and low-cost. Results are encouraging for fabrication of low cost, large format, and high performance dual band FPAs, making QWIP a stronger candidate in the competition for third generation thermal imagers

Excellent uniformity and mature material properties of Quantum Well Infrared Photodetectors (QWIPs) have allowed the realization of large format, low cost staring focal plane arrays (FPAs) in various thermal imaging bands. AlGaAs/InGaAs and AlGaAs/GaAs materials systems have been the standard systems for the construction of mid-wavelength infrared (MWIR) and long-wavelength (LWIR) QWIPs. However AlGaAs/GaAs QWIP FPAs suffer from low quantum and conversion efficiencies under high frame rate (low integration time) and/or low background conditions limiting the application area of standard QWIPs. This thesis focuses on the growth and development of InP based single and dual band QWIP FPAs. We experimentally demonstrate that QWIPs on InP substrates provide important advantages that can be utilized to overcome the bottlenecks of the standard GaAs based QWIP technology. InP/InGaAs material system is an alternative to AlGaAs/GaAs for LWIR QWIPs. We demonstrate a large format (640x512) LWIR QWIP FPA constructed with strained InP/InGaAs material system. The strain introduced to the structure shifts the cut-off wavelength from ~8.5 to 9.7 &micro / m with lambdap=8.9 &micro / m. The FPA fabricated with the 40-well epilayer structure yielded a peak quantum efficiency as high as 12% with a broad spectral response (&amp / #8710 / lambda/lambdap=17%). The peak responsivity of the FPA pixels is larger than 1.4 A/W with conversion efficiency as high as 20% in the bias region where the detectivity is reasonably high (2.6x1010 cmHz1/2/W, f/1.5, 65 K). The FPA providing a background limited performance temperature higher than 65 K (f/1.5) satisfies the requirements of most low integration time/low background applications where AlGaAs/GaAs QWIPs cannot be utilized due to low conversion efficiency and read-out circuit noise limited sensitivity. Noise equivalent temperature differences (NETD) of the FPA are as low as 19 and 40 mK with integration times as short as 1.8 ms and 430 &micro / s (f/1.5, 65 K), respectively. We also experimentally demonstrate that the cut-off wavelength of MWIR AlInAs/InGaAs QWIPs can be tuned in a sufficiently large range in the MWIR atmospheric window by only changing the quantum well (QW) width at the lattice matched composition. The cut-off wavelength can be shifted up to ~5.0 &micro / m with a QW width of 22 &Aring / in which case very broad spectral response (&amp / #8710 / lambda/lambdap=~30%) and a reasonably high peak detectivity is achievable leading to a NETD as low as 14 mK (f/2) with 25 &micro / m pitch in a 640x512 FPA. The advantages of InP based MWIR and LWIR single band QWIPs were combined by growing and fabricating a mid format (320x256) dual band QWIP FPA. The FPA provided NETD (f/1.5, 65 K, 19 ms) values of 27 mK and 29 mK in the MWIR and LWIR modes with an impressively low DC signal nonuniformity of ~ 4%. The results clearly demonstrate that InP based material systems display high potential for MWIR and LWIR single band and MWIR/LWIR dual band QWIP FPAs needed by third generation thermal imagers by overcoming the limitations of the standard GaAs based QWIPs under high frame rate (low integration time) and/or low background conditions.

The combat vehicle, CV90 has a semi-active hydraulic suspension system which uses inertial measurements for regulation to improve accessibility. To improve performance further measurements of future terrain can be used to, for example, prepare for impacts. This master's thesis investigates the ability to use existing sensors and new sensors to facilitate these measurements. Two test runs were performed, with very different conditions and outcomes. The results seem to suggest that a sweeping LIDAR was the most accurate and robust solution. However, using a very recent visual odometry algorithm, promising results were achieved using an Infra-red heat camera. Especially given that no efforts were put into adjusting parameters for that particular algorithm.