Characterization of Ground Deformation Associated with Shallow Groundwater Processes Using Satellite Radar Interferometry

Shallow groundwater processes maylead to ground deformation and even geohazards. With the features of day-and-night accessibility and large-scale coverage, time-series interferometric synthetic aperture radar (InSAR) has proven a useful tool for mapping the deformation over various landscapes at cm to mm level with weekly to monthly updates. However, it has limitations such as, decorrelation,atmospheric artifacts, topographic errors, andunwrapping errors, in particular for the hilly, vegetated, and complicated deformation patterns. In this dissertation, I focus on characterizing the ground deformation over landslides, aquifer systems, and mine tailings impoundment, using the designed advanced time-series InSAR strategy, as well as theinterdisciplinary knowledge of geodesy, hydrology, geophysics, and geology. Northwestern USA has been exposed to extreme landslide hazards due to steep terrain, high precipitation, and loose root support after wildfire. I characterize the rainfall-triggered movements of Crescent Lake landslide, Washington State. The seasonal deformation at the lobe, with larger magnitudes than the downslope riverbank, suggests an amplified hydrological loading effect due to a thicker unconsolidated zone. High-temporal-resolution InSAR and GPS data reveal dynamic landslide motions. Threshold rainfall intensities and durations wet seasons have been associated with observed movement upon shearing: antecedent rainfall triggered precursory slope-normal subsidence, and the consequent increase in pore pressure at the basal surface reduces friction and instigates downslope slip over the course of less than one month. In addition, a quasi-three-dimensional deformation field is created using multiple spaceborne InSAR observations constrained by the topographical slope, and is further used to invert for the complex geometry of landslide basal surface based on mass conservation. Aquifer skeletons deform in response to hydraulic head changes with various time scales of delay and sensitivity. I investigate the spatio-temporal correlation among deformation, hydrological records and earthquake records over Salt Lake Valley, Utah State. A clear long-term and seasonal correlation exists between surface uplift/subsidence and groundwater recharge/discharge, allowing me to quantify hydrogeological properties. Long-term uplift reflects the net pore pressure increase associated with prolonged water recharge, probably decades ago. The distributions of previously and newly mapped faults suggest that the faultsdisrupt the groundwater flow andpartition hydrological units. Mine tailings gradual settle as the pore pressure dissipates and the terrain subsides, andtailings embankment failures can be extremely hazardous. I investigate the dynamics of consolidation settlement over the tailings impoundment in the vicinity of Great Salt Lake, Utah State, as well as its associated impacts to the surrounding infrastructures. Largest subsidence has been observed around the low-permeable decant pond clay at the northeast corner.The geotechnical consolidation model reveals and predicts the long-term exponentially decaying settlement process. My studies have demonstrated that InSAR methods can advance our understanding about the potential anthropogenic impacts and natural hydrological modulations on various geodynamic settings in geodetic time scale

The Interferometric Use of Radar Sensors for the Urban Monitoring of Structural Vibrations and Surface Displacements

In this paper, we propose a combined use of real aperture radar (RAR) and synthetic aperture radar (SAR) sensors, within an interferometric processing chain, to provide a new methodology for monitoring urban environment and historical buildings at different temporal and spatial scales. In particular, ground-based RAR measurements are performed to estimate the vibration displacements and the natural oscillation frequencies of structures, with the aim of supporting the understanding of the building dynamic response. These measurements are then juxtaposed with ground-based and space-borne SAR data to monitor surface deformation phenomena, and hence, point out potential risks within an urban environment. In this framework, differential interferometric SAR algorithms are implemented to generate short-term (monthly) surface displacement and long-term (annual) mean surface displacement velocity maps at local (hundreds m2) and regional (tens km2) scale, respectively. The proposed methodology, developed among the activities carried out within the national project Programma Operativo Nazionale MASSIMO (Monitoraggio in Area Sismica di SIstemi MOnumentali), is tested and discussed for the ancient structure of Saint Augustine compound, located in the historical center of Cosenza (Italy) and representing a typical example of the Italian Cultural Heritage

Urban Deformation Monitoring using Persistent Scatterer Interferometry and SAR tomography

This book focuses on remote sensing for urban deformation monitoring. In particular, it highlights how deformation monitoring in urban areas can be carried out using Persistent Scatterer Interferometry (PSI) and Synthetic Aperture Radar (SAR) Tomography (TomoSAR). Several contributions show the capabilities of Interferometric SAR (InSAR) and PSI techniques for urban deformation monitoring. Some of them show the advantages of TomoSAR in un-mixing multiple scatterers for urban mapping and monitoring. This book is dedicated to the technical and scientific community interested in urban applications. It is useful for choosing the appropriate technique and gaining an assessment of the expected performance. The book will also be useful to researchers, as it provides information on the state-of-the-art and new trends in this fiel

Shuttle imaging radar-C science plan

The Shuttle Imaging Radar-C (SIR-C) mission will yield new and advanced scientific studies of the Earth. SIR-C will be the first instrument to simultaneously acquire images at L-band and C-band with HH, VV, HV, or VH polarizations, as well as images of the phase difference between HH and VV polarizations. These data will be digitally encoded and recorded using onboard high-density digital tape recorders and will later be digitally processed into images using the JPL Advanced Digital SAR Processor. SIR-C geologic studies include cold-region geomorphology, fluvial geomorphology, rock weathering and erosional processes, tectonics and geologic boundaries, geobotany, and radar stereogrammetry. Hydrology investigations cover arid, humid, wetland, snow-covered, and high-latitude regions. Additionally, SIR-C will provide the data to identify and map vegetation types, interpret landscape patterns and processes, assess the biophysical properties of plant canopies, and determine the degree of radar penetration of plant canopies. In oceanography, SIR-C will provide the information necessary to: forecast ocean directional wave spectra; better understand internal wave-current interactions; study the relationship of ocean-bottom features to surface expressions and the correlation of wind signatures to radar backscatter; and detect current-system boundaries, oceanic fronts, and mesoscale eddies. And, as the first spaceborne SAR with multi-frequency, multipolarization imaging capabilities, whole new areas of glaciology will be opened for study when SIR-C is flown in a polar orbit

Orbital differential SAR interferometry with polarimetric data

Space-borne Synthetic Aperture Radar (SAR) systems have demonstrated great effectiveness to survey wide areas, independently of the weather conditions and the day/night cycle. One of the most exploited applications is Differential SAR Interferometry (DInSAR), and by extension, advanced multi-temporal techniques addressed as Persistent Scatterers Interferometry (PSI). These techniques provide the means to retrieve the displacement on the observed terrain surface. Taking advantage of the high coverage provided by this technology, natural and human induced phenomena may be monitored and detected in order to avoid and prevent hazardous or even catastrophic situations. A good characterization of such events is often related to the density and quality of the information delivered. In many cases, the success in the interpretation of localized surface motion phenomena relies on having as much measurements as possible. Conventional insitu techniques, when used properly, are able to provide reliable measurements. However, they are limited to their localization, and deploy a high number of instruments is not cost effective. The good characterization provided by PSI measurements is limited by the acquisition parameters and the actual scene under monitoring. SAR images sensitivity over the scene depends strongly on the geometric shape and distribution of targets. Historically, satellite SAR sensors had single polarimetric capabilities, so sensitivity over the scene was restricted to a certain antenna configuration. On the contrary, polarimetric acquisitions emit an receive with different antenna configurations, providing sensitivity to different geometries in the scenario. The launch in these later years of several satellites with polarimetric capabilities has triggered its use in several fields of application. The objective of this thesis is to evaluate the use of Polarimetric SAR (PolSAR) data for its application in the PSI framework. The extra information contained in PolSAR datasets is bound to improve the effectiveness of PSI techniques. Obtaining a higher density and quality of motion measurements will ease the detection and interpretation of terrain displacement phenomena.Els Radars d'Obertura Sintètica (SAR) embarcats en satèl·lits han demostrat ser molt efectius per monitoritzar grans àrees, independentment de les condicions atmosfèriques i del cicle dia/nit. L'aplicació més explotada es l'Interferometria Diferencial SAR (DInSAR), i per extensió, les tècniques avançades de processament multi-temporal anomenades Interferometria de Reflectors Persistents (PSI). Aquestes tècniques són capaces de mesurar el desplaçament en superfície del terreny observat. Aprofitant la gran cobertura que s'aconsegueix amb aquesta tecnologia, fenòmens d'origen tant natural com humà poden ser detectats i controlats per evitar i prevenir situacions de perill o fins i tot catastròfiques. La bona caracterització d'aquestes situacions sovint es relaciona tant amb la densitat com en la qualitat de la informació obtinguda. En molts casos, l’èxit en la interpretació de moviments de terreny localitzats depèn de tenir tants punts de mesura com sigui possible. Les tècniques convencionals de mesura in-situ, quan s'usen de forma adequada, són capaces de donar mesures fiables. No obstant, la seva cobertura està limitada a la localització de l'instrument, i la instal·lació d’un gran nombre d'instruments no és una solució econòmica. La bona caracterització de l'àrea mesurada amb tècniques PSI està limitada pels paràmetres d'adquisició i les característiques de la pròpia escena observada. La sensitivitat de les imatges SAR depèn en gran mesura de la distribució i la forma geomètrica dels blancs mesurats. Històricament, els sensors SAR emetien en polarització simple, i per tant la sensitivitat a la escena estava restringida a aquesta configuració específica de la antena. Per altra banda, durant les adquisicions polarimètriques s'emet i es rep en diferents configuracions de l'antena. Això permet tenir sensitivitat a geometries diferents dins la mateixa escena. El llançament aquest últims anys de diferents satèl·lits amb capacitats polarimètriques ha permès el seu ús en diversos camps d'aplicació. L'objectiu d’aquesta tesi és avaluar l'ús de dades polarimètriques SAR (PolSAR) per la seva aplicació en el marc de les tècniques PSI. La informació addicional que contenen els conjunts d’adquisicions PolSAR ha de millorar l'efectivitat de les tècniques PSI. L'obtenció d'una millor densitat i qualitat de les mesures permet una millor detecció i interpretació dels fenòmens de desplaçament superficial del terreny.Postprint (published version