Interferometric Synthetic Aperture Radar Analysis And Elastic Modeling Of Deformation At The Svartsengi Geothermal Field In Iceland 1992 2010
Download Interferometric Synthetic Aperture Radar Analysis And Elastic Modeling Of Deformation At The Svartsengi Geothermal Field In Iceland 1992 2010 full books in PDF, epub, and Kindle. Read online free Interferometric Synthetic Aperture Radar Analysis And Elastic Modeling Of Deformation At The Svartsengi Geothermal Field In Iceland 1992 2010 ebook anywhere anytime directly on your device. Fast Download speed and no annoying ads. We cannot guarantee that every ebooks is available!
Analysis, Comparison, and Modeling of Radar Interferometry, Date of Surface Deformation Signals Associated with Underground Explosions, Mine Collapses and Earthquakes. Phase I
| Author | : |
| Publisher | : |
| Total Pages | : |
| Release | : 1999 |
| Genre | : |
| ISBN | : |
We have previously presented simple elastic deformation modeling results for three classes of seismic events of concern in monitoring the CTBT--underground explosions, mine collapses and earthquakes. Those results explored the theoretical detectability of each event type using synthetic aperture radar interferometry (InSAR) based on commercially available satellite data. In those studies we identified and compared the characteristics of synthetic interferograms that distinguish each event type, as well the ability of the interferograms to constrain source parameters. These idealized modeling results, together with preliminary analysis of InSAR data for the 1995 mb 5.2 Solvay mine collapse in southwestern Wyoming, suggested that InSAR data used in conjunction with regional seismic monitoring holds great potential for CTBT discrimination and seismic source analysis, as well as providing accurate ground truth parameters for regional calibration events. In this paper we further examine the detectability and ''discriminating'' power of InSAR by presenting results from InSAR data processing, analysis and modeling of the surface deformation signals associated with underground explosions. Specifically, we present results of a detailed study of coseismic and postseismic surface deformation signals associated with underground nuclear and chemical explosion tests at the Nevada Test Site (NTS). Several interferograms were formed from raw ERS-1/2 radar data covering different time spans and epochs beginning just prior to the last U.S. nuclear tests in 1992 and ending in 1996. These interferograms have yielded information about the nature and duration of the source processes that produced the surface deformations associated with these events. A critical result of this study is that significant post-event surface deformation associated with underground nuclear explosions detonated at depths in excess of 600 meters can be detected using differential radar interferometry. An immediate implication of this finding is that underground nuclear explosions may not need to be captured coseismically by radar images acquired before and after an event in order to be detectable. This has obvious advantages in CTBT monitoring since suspect seismic events--which usually can be located within a 100 km by 100 km area of an ERS-1/2 satellite frame by established seismic methods-can be imaged after the event has been identified and located by existing regional seismic networks. Key Words: InSAR, SLC images, interferogram, synthetic interferogram, ERS-1/2 frame, phase unwrapping, DEM, coseismic, postseismic, source parameters.
Deformation Monitoring Using Scanning Synthetic Aperture Radar Interferometry
| Author | : Krishna Vikas Gudipati |
| Publisher | : |
| Total Pages | : 394 |
| Release | : 2009 |
| Genre | : Interferometry |
| ISBN | : |
This dissertation provides the first demonstration of scanning synthetic aperture radar (ScanSAR) advanced interferometry processing for measuring surface deformation. ScanSAR data are synthesized from ERS-1/2 stripmap SAR images over known deformation in Phoenix, Arizona. The strategy is to construct a burst pattern similar to Envisat ScanSAR data and to create a realistic variable-burst synchronization scenario in which any image pair has at least 50% burst overlap. The Small Baseline Subsets technique is applied to the synthesized data to demonstrate ScanSAR time series analysis for a scenario generally conducive for interferometry. The same processing approach is employed with the stripmap data to validate the results. The differences in ScanSAR and stripmap velocities have a mean and standard deviation of 0.02"0.02 cm/year. 96.3% and 99.1% of the velocity differences are within "0.1 cm/year and "0.2 cm/year, respectively. The RMS deviations between the ScanSAR and stripmap displacement estimates are 0.40"0.30 cm. 68.5% and 94.6% of the differences are within "0.5 cm and "1.0 cm, respectively. The Permanent Scatterer (PS) technique also is adapted and applied to the synthesized data to demonstrate the presence of PS in ScanSAR data. The atmospheric and nonlinear motion phase derived from a PS analysis of stripmap data are removed from the ScanSAR interferograms. Even for this idealized scenario, the final PS identification yields fewer ScanSAR PS (10 PS/km2) than the stripmap PS results (312 PS/km2 or 15.6 PS/km2 at the ScanSAR pixel resolution). Based on the calculated likelihood of finding multiple stripmap PS within a ScanSAR pixel, it is concluded that the ScanSAR single scatterer PS model is flawed. A model is introduced that considers multiple PS within a ScanSAR pixel. The search for two PS per pixel yields 120 PS/km2. The ScanSAR and stripmap PS velocity differences mean is zero and standard deviation is 0.02 cm/year. However, while the differences between the ScanSAR and stripmap PS DEM error estimates are zero-mean, they have a 7-meter standard deviation. One possible explanation for this relatively large deviation is the differencing of the wrong ScanSAR and stripmap PS as the result of a misalignment between the ScanSAR and stripmap images.
Inversion of Synthetic Aperture Radar Interferograms for Sources of Production-Related Subsidence at the Dixie Valley Geothermal Field
| Author | : |
| Publisher | : |
| Total Pages | : 11 |
| Release | : 2003 |
| Genre | : |
| ISBN | : |
We used synthetic aperture radar interferograms to image ground subsidence that occurred over the Dixie Valley geothermal field during different time intervals between 1992 and 1997. Linear elastic inversion of the subsidence that occurred between April, 1996 and March, 1997 revealed that the dominant sources of deformation during this time period were large changes in fluid volumes at shallow depths within the valley fill above the reservoir. The distributions of subsidence and subsurface volume change support a model in which reduction in pressure and volume of hot water discharging into the valley fill from localized upflow along the Stillwater range frontal fault is caused by drawdown within the upflow zone resulting from geothermal production. Our results also suggest that an additional source of fluid volume reduction in the shallow valley fill might be similar drawdown within piedmont fault zones. Shallow groundwater flow in the vicinity of the field appears to be controlled on the NW by a mapped fault and to the SW by a lineament of as yet unknown origin.
Phase Unwrapping and Inversion Resolution of Interferometric Synthetic Aperture Radar Geodesy
| Author | : Philip Nee |
| Publisher | : |
| Total Pages | : 93 |
| Release | : 2012 |
| Genre | : |
| ISBN | : |
We use Interferometric Synthetic Aperture Radar (InSAR) data to examine surface deformation in the Imperial Valley, California, with the goal of further constraining the fault geometry and along-strike variations in slip behavior of the Imperial fault. 48 Interferograms are created from 38 European Space Agency (EAS) Envisat ASAR acquisitions, spanning 7 years. We observe extensive agriculture activities in the Imperial Valley, and geothermal and ground-water related subsidence. However, no prominent tectonic deformation signals can be identified in the valley due to 1: Poor-quality InSAR data due to extensive agricultural activity, and 2: the lack of GPS measurements at the spatial and temporal densities required to fully characterize behavior of the Imperial fault. Due to technical difficulties of InSAR, spatial variation in data density in the Imperial valley greatly affects our data quality and numerical resolution. To ensure our results are robust, we perform synthetic tests to examine the numerical resolution and data quality of a given data set. The results can later be used as quality assessments and validation for our results. The point-target identification method that allows us to extract the stable pixels from interferogram time series as well as approaches for masking out less stable areas so that they do not contaminate our results in the rest of the region, is also being tested. In the case study, we examine deformation across the Superstitution Hills Fault and a deformation source near the Salton Sea, potentially caused by geothermal activities. The vicinity near the Superstitution Hills fault is deforming at peak velocity of ~8mm/yr, revealing a prominent fault trace, and the geothermal deformation is moving at ~6mm/yr, both rates taken in the direction of the satellite line-of-site (LOS).
Inversion of Synthetic Aperture Radar Interferograms for Sourcesof Production-related Subsidence at the Dixie Valley Geothermalfield
| Author | : |
| Publisher | : |
| Total Pages | : |
| Release | : 2006 |
| Genre | : |
| ISBN | : |
We used synthetic aperture radar interferograms to imageground subsidence that occurred over the Dixie Valley geothermal fieldduring different time intervals between 1992 and 1997. Linear elasticinversion of the subsidence that occurred between April, 1996 and March,1997 revealed that the dominant sources of deformation during this timeperiod were large changes in fluid volumes at shallow depths within thevalley fill above the reservoir. The distributions of subsidence andsubsurface volume change support a model in which reduction in pressureand volume of hot water discharging into the valley fill from localizedupflow along the Stillwater range frontal fault is caused by drawdownwithin the upflow zone resulting from geothermal production. Our resultsalso suggest that an additional source of fluid volume reduction in theshallow valley fill might be similar drawdown within piedmont faultzones. Shallow groundwater flow in the vicinity of the field appears tobe controlled on the NW by a mapped fault and to the SW by a lineament ofas yet unknown origin.
Using Interferometric Synthetic Aperture Radar Data to Improve Estimates of Hydraulic Head in the San Luis Valley, Colorado
| Author | : Jessica Anne Reeves |
| Publisher | : |
| Total Pages | : |
| Release | : 2013 |
| Genre | : |
| ISBN | : |
Remotely sensed Interferometric Synthetic Aperture Radar (InSAR) deformation data have recently been used to study confined aquifer systems in urban/arid areas. The deformation measured at the surface by InSAR is a consequence of changes in hydraulic head in the underlying confined aquifer system. Deformation in agricultural areas, such as the San Luis Valley, Colorado, is difficult to measure using InSAR because changes in the height of the vegetation can degrade the measurement by altering the positions of individual radar scatterers. Nonetheless, agricultural areas like the San Luis Valley are of great interest because of the link between the groundwater resources and the local economy. The San Luis Valley is an 8000 km^2 valley, located mostly on the northern side of the Colorado-New Mexico border. The valley has a vibrant agricultural economy that is highly dependent on the effective management of limited water resources. State regulation established that hydraulic head levels within the confined aquifer system should be maintained within the range experienced in the years between 1978 and 2000. Effective management of water resources in the San Luis Valley requires both seasonal changes in hydraulic head as well long term trends during this time period. In this study we had three main goals: 1) to determine if high quality InSAR data can be collected in the San Luis Valley, 2) to determine the uncertainty of the InSAR deformation measurements, and 3) to determine to what extent the InSAR deformation data can be used to improve estimates of hydraulic head in the San Luis Valley. We found that high quality InSAR data could be acquired from the San Luis Valley. Many small areas, left unwatered by the center-pivot irrigation systems, yield high quality InSAR data when processed using Small Baseline Subset analysis. The InSAR deformation measurements showed the same seasonal periodicity as the hydraulic head data from monitoring wells. The next step in our research was to more accurately determine the uncertainty in the InSAR deformation measurements. We developed a novel algorithm that uses supplementary hydrologic data to identify InSAR acquisitions whose measurements may have been corrupted with uncertainty due to atmospheric phase effects. We then proceeded to quantify the uncertainty in the InSAR deformation measurement due to decorrelation of radar signals. In the final chapter of this work we explored ways in which the relationship between InSAR measured deformation and measurements of hydraulic head can be combined to increase the spatial and temporal density of hydraulic head measurements in the confined aquifer system. We found that at three well locations where the changes in hydraulic head were sufficiently large and the aquifer sediments were relatively compressible the InSAR deformation measurements can be reliably used to estimate hydraulic head during times when no well measurements were acquired.
