The variable contexts of Fremont habitation sites in Utah Valley often make identification of those sites very challenging for archaeologists. Pit houses and other structures throughout the valley are frequently in plowed fields or other disturbed contexts that obscure their more exact location and nature. The application of geophysical technologies at archaeological sites throughout the world, including in North America, has proven to be an effective means of subsurface archaeological survey. However, geophysical techniques have been underutilized in Fremont archaeology. This paper reports on the employment of two geophysical methods, ground-penetrating radar (GPR) and fluxgate gradiometer surveys, at three known Fremont habitation sites in southern Utah Valley – the Wolf Village, Wolf Mound, and Snow Farm sites. The preliminary geophysical surveys and later ground-truthing of various geophysical anomalies reveals the effectiveness of these methods in identifying where architectural or other cultural features exist below the surface.

Ground penetrating radar (GPR) is limited by depth penetration and signal-to-noise ratio (SNR), impacting the ability to resolve subsurface features. Stacking, a process of averaging multiple scans in the same location, improves SNR. Digital antennas are capable of stacking at much higher rates than analog antennas. Four sites were examined using a GSSI SIR-4000 GPR unit with a 400 MHz analog antenna and a 350 MHz digital “hyperstacking” (350 HS) antenna. Sites represent various soil conditions, with known features. Data were compared qualitatively and quantitatively for differences in antenna outputs. Visual inspection of radargrams indicate a reduction in noise in the 350 HS data compared to the 400 MHz data. Quantitative assessments identified significant differences in standard deviation of radar reflection amplitude occurring at depth with both antennas and a reduction in noise and marginal increases in depth of penetration in low-loss conditions with the 350 MHz HS antenna.

L’objectif de la thèse est d’améliorer les différents traitements et de proposer une visualisation claire et intuitive à l’opérateur des données en sortie d’un géoradar (radargramme) afin de pouvoir localiser de manière précise les réseaux de canalisations enfouis. Notamment, nous souhaitons mettre en évidence les hyperboles présentes dans les radargrammes car celles-ci sont caractéristiques de la présence d'une canalisation. Dans un premier temps nous nous sommes intéressés à la suppression de l’information inutile (clutter) pouvant gêner la détection des hyperboles. Nous avons ainsi proposé une méthode de filtrage du clutter et du bruit des radargrammes. Ensuite, nous avons travaillé sur l’élaboration d’une méthode permettant de détecter automatiquement les hyperboles dans un radargramme ainsi qu’une estimation de sa fonction mathématique dans des conditions quasi-temps réel. Et enfin nous avons également proposé une méthode de séparation de source permettant de distinguer le clutter et le signal utile du radargramme tout en ayant un impact minimal sur les hyperboles. Ces derniers travaux ouvrent d’autres possibilités pour le filtrage, le rehaussement ou la détection automatique d’hyperboles. / The thesis objective is to improve the different processing in order to make the data acquired by ground penetrating radar (B-scan) more understandable for the operators. Consequently, it will facilitate the pipe localisation. More particularly, we wish to highlight the hyperbolas in the B-scan because they point out the presence of a pipe. First of all, we are interested in removing all the useless information which might hide the hyperbolas. We proposed a filtering method removing unwanted reflections and noise. Then, we worked on an automatic hyperbola detection method and an estimation of their mathematical functions in quasi real time. Finally, we proposed a source separation method to distinguish the unwanted reflections from the hyperbolas with a minimal impact on them. This last work opens interesting perspectives in filtering, hyperbolas enhancement and hyperbola detection.

Antarctic debris-covered glaciers are potential archives of long-term climate change. However, the geomorphic response of these systems to climate forcing is not well understood. To address this concern, I conducted a series of field-based and numerical modeling studies in the McMurdo Dry Valleys of Antarctica (MDV), with a focus on Mullins and Friedman glaciers. I used data and results from geophysical surveys, ice-core collection and analysis, geomorphic mapping, micro-meteorological stations, and numerical-process models to (1) determine the precise origin and distribution of englacial and supraglacial debris within these buried-ice systems, (2) quantify the fundamental processes and feedbacks that govern interactions among englacial and supraglacial debris, (3) establish a process-based model to quantify the inventory of cosmogenic nuclides within englacial and supraglacial debris, and (4) isolate the governing relationships between the evolution of englacial /supraglacial debris and regional climate forcing. Results from 93 field excavations, 21 ice cores, and 24 km of ground-penetrating radar data show that Mullins and Friedman glaciers contain vast areas of clean glacier ice interspersed with inclined layers of concentrated debris. The similarity in the pattern of englacial debris bands across both glaciers, along with model results that call for negligible basal entrainment, is best explained by episodic environmental change at valley headwalls. To constrain better the timing of debris-band formation, I developed a modeling framework that tracks the accumulation of cosmogenic 3He in englacial and supraglacial debris. Results imply that ice within Mullins Glacier increases in age non-linearly from 12 ka to ~220 ka in areas of active flow (up to >> 1.6 Ma in areas of slow-moving-to-stagnant ice) and that englacial debris bands originate with a periodicity of ~41 ka. Modeling studies suggest that debris bands originate in synchronicity with changes in obliquity-paced, total integrated summer insolation. The implication is that the englacial structure and surface morphology of some cold-based, debris-covered glaciers can preserve high-resolution climate archives that exceed the typical resolution of Antarctic terrestrial deposits and moraine records.

Les travaux présentés dans cette thèse portent sur les résolutions des problèmes direct et inverse associés à l’étude du radar de sol (GPR). Ils s’inscrivent dans un contexte d’optimisation des performances et d’amélioration de la qualité de l’imagerie. Un état de l’art est réalisé et l’accent est mis sur les méthodes de simulation et les techniques d’imagerie appliquées dans le GPR. L’étude de l’utilisation de la méthode du Galerkin discontinue (GD) pour la simulation GPR est d’abord réalisée. Des scénarios complets de GPR sont considérés et les simulations GD sont validées par comparaison avec des données obtenues par CST-MWS et des mesures. La suite de l’étude concerne la résolution du problème inverse en utilisant le Linear Sampling Method (LSM) pour l’application GPR. Une étude avec des données synthétiques est d’abord réalisée afin de valider et tester la fiabilité du LSM. Finalement, le LSM est adapté pour des applications GPR en prenant en compte les caractéristiques du rayonnement de l’antenne ainsi que ses paramètres S. Finalement, une étude est effectuée pour prouver la détectabilité de la jonction d‘un câble électrique souterrain dans un environnement réel. / The work presented in this thesis deals with the resolutions of the direct and inverse problems of the ground radar (GPR). The objective is to optimize GPR’s performance and its imaging quality. A state of the art of ground radar is realized. It focused on simulation methods and imaging techniques applied in GPR. The study of the use of the discontinuous Galerkin (GD) method for the GPR simulation is first performed. Some scenarios complete of GPR are considered and the GD simulations are validated by comparing the same scenarios’ modeling with CST-MWS and the measurements. Then a study of inverse problem resolution using the Linear Sampling Method (LSM) for the GPR application is carried out. A study with synthetic data is first performed to test the reliability of the LSM. Then, the LSM is adapted for the GPR application by taking into account the radiation of antenna. Finally, a study is designed to validate the detectability of underground electrical cables junction with GPR in a real environment.

abstract: Water is one of, if not the most valuable natural resource but extremely challenging to manage. According to old research in the field, many Water Distribution Systems (WDSs) around the world lose above 40 percent of clean water pumped into the distribution system because of unfortune leaks before the water gets anywhere from the fresh water resources. By reducing the amount of water leaked, distribution system managers can reduce the amount of money, resources, and energy wasted on finding and repairing the leaks, and then producing and pumping water, increase system reliability and more easily satisfy present and future needs of all consumers. But having access to this information pre-amatively and sufficiently can be complex and time taking. For large companies like SRP who are moving tonnes of water from various water bodies around phoenix area, it is even more crucial to efficiently locate and characterize the leaks. And phoenix being a busy city, it is not easy to go start digging everywhere, whenever a loss in pressure is reported at the destination. Keeping this in mind, non-invasive methods to geo-physically work on it needs attention. There is a lot of potential in this field of work to even help with environmental crisis as this helps in places where water theft is big and is conducted through leaks in the distribution system. Methods like Acoustic sensing and ground penetrating radars have shown good results, and the work done in this thesis helps us realise the limitations and extents to which they can be used in the phoenix are. The concrete pipes used by SRP are would not be able to generate enough acoustic signals to be affectively picked up by a hydrophone at the opening, so the GPR would be helpful in finding the initial location of the leak, as the water around the leak would make the sand wet and hence show a clear difference on the GPR. After that the frequency spectrum can be checked around that point which would show difference from another where we know a leak is not present. / Dissertation/Thesis / Masters Thesis Mechanical Engineering 2019

Bison produce trails, wallows, and trample grounds, visible in satellite imagery disturbing ~27,500 m2 at Yellowstone National Park (YNP; in USA) and ~10,700 m2 in Białowieża National Forest (BNF; in Poland and Belarus), and, without anthropogenic land change, these mega-traces persist in sand-dominated substrates for 6-26 years. The average wallow size ranges from ~17-40 m2, whereas the average trample ground varies in size from ~140-300 m2. Trail segments typically extend for ~260-380 m, but the longest trails at YNP traverse >3 km. Estimates of track volume indicate for a standard herd of 200 animals, over a daily distance of 10 km ~4000 m3 is pediturbated. Low sinuosity values of 1.16-1.10 characterize trails, and wallows display high aspect ratios >0.7, helping distinguish bison traces on the landscape. During the Holocene, as many as 40 million bison inhabited North America, so this study provides a qualitative baseline for considering the geomorphic ability of large ungulates.Caliper measurements indicate the surface expression of simulated bison tracks varies depending on the moisture content of the medium. The slope of the marginal ridges (MR) in dry (0% moisture by volume), moist (~10% moisture by volume) and wet (saturated) sand differ around the track perimeter, although the minimum slope of the marginal ridge increases with moisture content (dry sand ~10 cm, moist sand ~40 cm, wet sand ~20 cm). The maximum MR slope (~80°) occurs in a moist substrate. The aspect ratio of prints in wet sand is 0.60, reflecting the most elliptical hoofprint, whereas moist sand displayed the most circular track with an aspect ratio of 0.76. The interdigital angle decreased by ~5° with increasing moisture (dry = 56°, wet ≈ 51°). Photos document in dry sand, deformation fronts 2-3 cm in height are present, whereas in moist sand, transverse and radial cracks are present. In wet sand, debris flows form. Ground-penetrating radar (GPR) imaging reveals subsurface anomalies interpreted as undertracks and normal micro-faults. In dry sand, two poorly-defined sets of undertracks with 1 cm relief are visible 3-4 cm beneath the tracking surface. Normal faulting is absent. In moist and wet sand, 4-5 sets of detailed undertracks showing 2-3 cm of relief deform sediments 7-8 cm in depth. Several normal faults are present in moist and wet hoofprints. Combined surface and subsurface observations may indicate the moisture content of paleo-tracking surfaces, particularly if the substrate is saturated. When hoofprints are formed in an unfrozen substrate, freezing increases preservation potential. Partially thawed tracks are resistant to deflation (wind erosion), maintaining outlines of digits and the medial pocket until late stages of deflation. Billions of ungulate traces formed in aeolian periglacial settings may be preserved. Tracks exposed to aeolian action exhibit higher heavy-mineral concentrations (HMC) along marginal ridges (MR), which are detectable using low-field bulk magnetic susceptibility (MS). In situ tracks from Delaware and Virginia (USA) display marginal HMCs 3.7-10x greater than background MS, whereas in laboratory, simulated hoofprints show marginal HMCs 1.7x above background MS. HMCs readily occur in nature, so MS measurements of tracking surfaces may quantitatively indicate the length or intensity of aeolian processes. This experiment demonstrates hoofprints indented through a <1 mm thick HMC and subsequently exposed to 1 min wind gusts of 5-10 m/s form HMCs on the scale of 10’s of µSI. Billions of ungulate tracks displaying marginal HMCs are probably preserved, potentially providing a detailed regional paleo-wind record. / Geoscience

Drone-mounted ground penetrating radar (GPR) has the capability to investigate terrain that is inaccessible or hazardous to humans. A linear frequency-modulated (LFM) radar with the potential for GPR applications is described based on the LimeSDR Mini software defined radio (SDR). Challenges of the LimeSDR Mini radar include the SDR's lack of support for transmitter-receiver synchronization and high bleedthrough leakage. These issues are overcome through corrective software processing techniques including deconvolution of the SDR's system impulse response and digital feed-through nulling. Feed-through nulling is effective at reducing bleedthrough leakage, achieving a 26 dB reduction in power. Although high noise can confound the identification of targets with small radar cross sections in dynamic environments, the LimeSDR Mini radar is demonstrated to display a moving target across multiple ranges. This research demonstrates the increasing accessibility of SDR radar for drone applications, as the LimeSDR Mini is lightweight and low-cost compared to high-end SDRs typically used in SDR radar.

No description available.

Ground-penetrating radar (GPR) and magnetometry were used at Tel Shimron, an archaeological site in Israel’s Jezreel Valley. GPR primarily measures electric properties while magnetometry measures magnetic properties, making them complementary methods for subsurface prospection. Magnetometry can be collected and processed quickly, making it an ideal landscape-scale reconnaissance tool. It takes more time to collect, process, and interpret GPR data, but the result is a higher resolution dataset. In addition, GPR often works better than magnetometry in desert environments such as the Jezreel Valley. Conventional wisdom suggests that GPR should not be used as a landscape-scale reconnaissance tool unless there is ample time to process and interpret the data. Despite this, GPR was used at Tel Shimron with standardized, semi-automated processing routines and eight field technicians to produce an end product. The GPR survey revealed more about the subsurface than magnetometry, including three potential dwellings and a Bronze Age city gate.