The Utility of Synthetic Aperture Radar (SAR) Interferometry in Monitoring Sinkhole Subsidence: Subsidence of the Devil's Throat Sinkhole Area (Nevada, USA)

Electromagnetic Waves ◽

Forest Canopy ◽

Thermal State ◽

Time Lag ◽

Sar Interferometry ◽

Synthetic Aperture ◽

Dimensional Structure ◽

Forest Mapping ◽

A synthetic aperture radar (SAR) is an active sensor transmitting pulses of polarized electromagnetic waves and receiving the backscattered radiation. SAR sensors at different wavelengths and with different polarimetric capabilities are being used in remote sensing of the earth. The value of an analysis of backscattered energy alone is limited due to ambiguities in the possible ecological factor configurations causing the signal. From two SAR images taken from similar viewing positions with a short time-lag, interference between the two waves can be observed. By subtracting the two phases of the signals, it is feasible to eliminate the random contribution of the scatterers to the phase. The interferometric correlation and the interferometric phase contain additional information on the three-dimensional structure of the scattering elements in the imaged area. A brief review of SAR sensors is given, followed by an outline of the physical foundations of SAR interferometry and the practical data-processing steps involved. An overview of applications of InSAR to forest mapping and monitoring is given, covering tree-bole volume and biomass, forest types and land cover, fire scars, forest thermal state and forest canopy height.

Transient active deformation in Tainan tableland using persistent scatterers SAR interferometry

BSGF - Earth Sciences Bulletin ◽

10.2113/gssgfbull.184.4-5.441 ◽

2013 ◽

Vol 184 (4-5) ◽

pp. 441-450 ◽

Cited By ~ 4

Author(s):

Yu-Yia Wu ◽

Jyr-Ching Hu ◽

Geng-Pei Lin ◽

Chung-Pai Chang ◽

Hsin Tung ◽

...

Keyword(s):

Surface Deformation ◽

Sar Interferometry ◽

Synthetic Aperture ◽

Uplift Rate ◽

Active Deformation ◽

Radar Images ◽

Persistent Scatterers ◽

Area North ◽

Abstract Persistent scatterers SAR interferometry (PS-InSAR) was employed to monitor surface deformation in and around the Tainan tableland using 20 advanced synthetic aperture radar (ASAR) images from the ENVISAT satellite taken during the period from 2005 May 19 to 2008 September 25. In our study, we have found that the uplift rate of the northern Tainan tableland is faster than the southern tableland. The slant range displacement (SRD) rate for the area north along the precise leveling array is about 5 to 10 mm/yr with respect to the western edge of the Tainan tableland, whereas the SRD rate for the area south of the leveling array is about 1 to 5 mm/yr. In addition, the uplifted area extends eastward to the Tawan lowland with a maximum SRD rate of nearly 10 mm/yr, which is almost the same as the rate of the Tainan tableland. Results of this study differ from those suggested in previous researches that employed ERS-1/2 radar images taken from 1996 to 1999 and the differential interferometry synthetic aperture radar (D-InSAR) technique. Our findings indicated that the Tawan lowland no longer subsides with respect to the western edge of the Tainan tableland, and that both northern and southern areas are experiencing uplift.

Synthetic Aperture Radar (SAR) Interferometry for Assessing Wenchuan Earthquake (2008) Deforestation in the Sichuan Giant Panda Site

Remote Sensing ◽

10.3390/rs6076283 ◽

2014 ◽

Vol 6 (7) ◽

pp. 6283-6299 ◽

Cited By ~ 7

Author(s):

Fulong Chen ◽

Huadong Guo ◽

Natarajan Ishwaran ◽

Wei Zhou ◽

Ruixia Yang ◽

...

Keyword(s):

Wenchuan Earthquake ◽

Giant Panda ◽

Sar Interferometry ◽

Synthetic Aperture ◽

Fusion of SAR Interferometry and Polarimetry Methods for Landslide Reactivation Study, the Bureya River (Russia) Event Case Study

Remote Sensing ◽

10.3390/rs13245136 ◽

2021 ◽

Vol 13 (24) ◽

pp. 5136

Author(s):

Valery Bondur ◽

Tumen Chimitdorzhiev ◽

Aleksey Dmitriev ◽

Pavel Dagurov

Keyword(s):

Radar Data ◽

Sar Interferometry ◽

Synthetic Aperture ◽

Line Of Sight ◽

Scattering Mechanisms ◽

Radar Images ◽

Landslide Reactivation ◽

Sbas Insar ◽

In this paper, we demonstrate the estimation capabilities of landslide reactivation based on various SAR (Synthetic Aperture Radar) methods: Cloude-Pottier decomposition of Sentinel-1 dual polarimetry data, MT-InSAR (Multi-temporal Interferometric Synthetic Aperture Radar) techniques, and cloud computing of backscattering time series. The object of the study is the landslide in the east of Russia that took place on 11 December 2018 on the Bureya River. H-α-A polarimetric decomposition of C-band radar images not detected significant transformations of scattering mechanisms for the surface of the rupture, whereas L-band radar data show changes in scattering mechanisms before and after the main landslide. The assessment of ground displacements along the surface of the rupture in the 2019–2021 snowless periods was carried out using MT-InSAR methods. These displacements were 40 mm/year along the line of sight. The SBAS-InSAR results have allowed us to reveal displacements of great area in 2020 and 2021 snowless periods that were 30–40 mm/year along the line-of-sight. In general, the results obtained by MT-InSAR methods showed, on the one hand, the continuation of displacements along the surface of the rupture and on the other hand, some stabilization of the rate of landslide processes.

Glacier displacement on Comfortlessbreen, Svalbard, using 2-pass differential SAR interferometry (DInSAR) with a digital elevation model

Polar Record ◽

10.1017/s0032247411000453 ◽

2011 ◽

Vol 48 (1) ◽

pp. 17-25 ◽

Cited By ~ 4

Author(s):

Nora Jennifer Schneevoigt ◽

Monica Sund ◽

Wiley Bogren ◽

Andreas Kääb ◽

Dan Johan Weydahl

Keyword(s):

Digital Elevation Model ◽

Sar Interferometry ◽

Synthetic Aperture ◽

Synthetic Aperture Radar Interferometry ◽

Glacier Terminus ◽

Digital Elevation ◽

Reference Images ◽

Elevation Model ◽

ABSTRACTDifferential synthetic aperture radar interferometry (DInSAR) exploits the coherence between the phases of two or more satellite synthetic aperture radar (SAR) scenes taken from the same orbit to separate the phase contributions from topography and movement by subtracting either phase. Hence pure terrain displacement can be derived without residual height information in it, but only the component of movement in line-of-sight direction is represented in a differential interferogram. Comfortlessbreen, a recently surging glacier, flows predominantly in this direction with respect to the European Remote Sensing satellites ERS-1 and ERS-2. Four C-band SAR scenes from spring 1996 were selected because of the high coherence between the respective pairs of the 1-day repeat-pass tandem mission of the ERS sensors. 2-pass DInSAR is performed in combination with a SPOT5 (Satéllite pour l'Observation de la Terre 5) SPIRIT (SPOT5 stereoscopic survey of Polar Ice: Reference Images and Topography) digital elevation model (DEM) from 2007. The different processing steps and intermediate image products, including unwrapping and generation of displacement maps, are detailed in order to convey the DInSAR processing chain to the beginner in the field of interferometry. Maximum horizontal displacements of 18 to 20 cm d−1 in ground range direction can be detected at the glacier terminus, while a few centimetres per day characterised most of the middle and upper portions of Comfortlessbreen in spring 1996.

Investigating landslides with space-borne Synthetic Aperture Radar (SAR) interferometry

Engineering Geology ◽

10.1016/j.enggeo.2006.09.013 ◽

2006 ◽

Vol 88 (3-4) ◽

pp. 173-199 ◽

Cited By ~ 382

Author(s):

Carlo Colesanti ◽

Janusz Wasowski

Keyword(s):

Sar Interferometry ◽

Synthetic Aperture ◽

LiCSAR: An Automatic InSAR Tool for Measuring and Monitoring Tectonic and Volcanic Activity

Remote Sensing ◽

10.3390/rs12152430 ◽

2020 ◽

Vol 12 (15) ◽

pp. 2430 ◽

Cited By ~ 3

Author(s):

Milan Lazecký ◽

Karsten Spaans ◽

Pablo J. González ◽

Yasser Maghsoudi ◽

Yu Morishita ◽

...

Keyword(s):

Data Storage ◽

Large Scale ◽

Surface Deformation ◽

Sar Interferometry ◽

Synthetic Aperture ◽

Online Portal ◽

Processing And Storage ◽

Update Strategy ◽

Space-borne Synthetic Aperture Radar (SAR) Interferometry (InSAR) is now a key geophysical tool for surface deformation studies. The European Commission’s Sentinel-1 Constellation began acquiring data systematically in late 2014. The data, which are free and open access, have global coverage at moderate resolution with a 6 or 12-day revisit, enabling researchers to investigate large-scale surface deformation systematically through time. However, full exploitation of the potential of Sentinel-1 requires specific processing approaches as well as the efficient use of modern computing and data storage facilities. Here we present Looking Into Continents from Space with Synthetic Aperture Radar (LiCSAR), an operational system built for large-scale interferometric processing of Sentinel-1 data. LiCSAR is designed to automatically produce geocoded wrapped and unwrapped interferograms and coherence estimates, for large regions, at 0.001° resolution (WGS-84 coordinate system). The products are continuously updated at a frequency depending on prioritised regions (monthly, weekly or live update strategy). The products are open and freely accessible and downloadable through an online portal. We describe the algorithms, processing, and storage solutions implemented in LiCSAR, and show several case studies that use LiCSAR products to measure tectonic and volcanic deformation. We aim to accelerate the uptake of InSAR data by researchers as well as non-expert users by mass producing interferograms and derived products.

Estimation of Deformation Intensity above a Flooded Potash Mine Near Berezniki (Perm Krai, Russia) with SAR Interferometry

Remote Sensing ◽

10.3390/rs12193215 ◽

2020 ◽

Vol 12 (19) ◽

pp. 3215

Author(s):

Sergey Samsonov ◽

Alexandr Baryakh

Keyword(s):

Ground Deformation ◽

Measurement Techniques ◽

Sar Interferometry ◽

Synthetic Aperture ◽

Ground Subsidence ◽

Synthetic Aperture Radar Data ◽

Perm Krai ◽

Potash Mine ◽

In this study we used RADARSAT-2 and Sentinel-1 Synthetic Aperture Radar data for measuring subsidence above a flooded potash mine, which is almost entirely located within the city of Berezniki (Perm Krai, Russia), population 150,000. This area has experienced very fast subsidence since October 2006 when the integrity of the Berezniki-1 mine was compromised, resulting in water intrusion, subsequent flooding and closure of the mine. Due to the ongoing dissolution of carnallite, subsidence in this region is expected to continue in the foreseeable future. In addition to rapid subsidence, at least five sinkholes have formed in the region, with the largest being 440 × 320 m. We observed ground subsidence during the period October 2011–April 2014 (RADARSAT-2) with a vertical rate up to 14 cm/year and horizontal rate up to 10 cm/year; during the period July 2016–June 2020 (Sentinel-1) with a vertical rate up to 17 cm/year. Our results were validated by precise leveling, with a coefficient of correlation of 0.75. Subsidence faster than 17 cm/year observed by precise leveling was not resolvable with Differential Interferometric Synthetic Aperture Radar (DInSAR). Our results show the complementary nature of ground-based and space-borne measurement techniques. The precise leveling captures subsidence along profile lines with high precision but lower temporal resolution, while DInSAR captures subsidence with high spatial and temporal resolutions but with lower precision. DInSAR is also significantly affected by decorrelation outside of urban areas. An important advantage of our methodology is the ability to measure the horizontal east component of the ground deformation when both, ascending and descending, data are available. This measurement directly characterizes the level of anthropogenic load on buildings and infrastructure. We recommend continuing monitoring subsidence using both measurement techniques, which can also be complemented by continuous Global Navigation Satellite System (GNSS).

Spatial and temporal subsidence characteristics in Wuhan (China), during 2015–2019, inferred from Sentinel-1 synthetic aperture radar (SAR) interferometry

Natural Hazards and Earth System Science ◽

10.5194/nhess-21-2285-2021 ◽

2021 ◽

Vol 21 (8) ◽

pp. 2285-2297

Author(s):

Xuguo Shi ◽

Shaocheng Zhang ◽

Mi Jiang ◽

Yuanyuan Pei ◽

Tengteng Qu ◽

...

Keyword(s):

Urban Expansion ◽

Sar Interferometry ◽

Synthetic Aperture ◽

Ground Subsidence ◽

Karst Collapse ◽

Jianghan Plain ◽

Soft Foundation ◽

Interferometric Sar ◽

Abstract. Ground subsidence is regarded as one of the most common geohazards, accompanied with the rapid urban expansion in recent years. In the last 2 decades, Wuhan, located in the alluvial Jianghan Plain, has experienced great urban expansion with increased subsidence issues, i.e., soft foundation subsidence and karst collapse. Here we investigated subsidence rates in Wuhan with 2015–2019 Sentinel-1 synthetic aperture radar (SAR) images. We found that the overall subsidence over the Wuhan region is significantly correlated with the distribution of engineering geological subregions (EGSs). We further validated the interferometric SAR (InSAR) measurements with better than 5 mm accuracy by comparing with leveling measurements. Subsidence centers in Qingling–Jiangdi, Houhu, Qingshan, and Dongxihu were identified with displacement rates of approximately 30 mm/yr. Our results demonstrated that the dominant driving factor is ongoing construction, and the fact that the subsidence centers shifted with construction intensities. The Qingling–Jiangdi area in our study is a well-known site of karst collapse. We find that the nonlinear subsidence of this area is correlated with the seasonal rainfall.

ScanSAR Interferometry of the Gaofen-3 Satellite with Unsynchronized Repeat-Pass Images

Sensors ◽

10.3390/s19214689 ◽

2019 ◽

Vol 19 (21) ◽

pp. 4689 ◽

Cited By ~ 1

Author(s):

Sun ◽

Yu ◽

Dong ◽

Luo

Keyword(s):

Phase Error ◽

Control Point ◽

Closed Form Solution ◽

Form Solution ◽

Sar Interferometry ◽

Synthetic Aperture ◽

Image Pair ◽

Phase Compensation ◽

Gaofen-3 is a Chinese remote sensing satellite with multiple working modes, among which the scanning synthetic aperture radar (ScanSAR) mode is used for wide-swath imaging. synthetic aperture radar (SAR) interferometry in the ScanSAR mode provides the most rapid way to obtain a global digital elevation model (DEM), which can also be realized by Gaofen-3. Gaofen-3 ScanSAR interferometry works in the repeat-pass mode, and image pair non-synchronizations can influence its performance. Non-synchronizations can include differences of burst central times, satellite velocities, and burst durations. Therefore, it is necessary to analyze their influences and improve the interferometric coherence. Meanwhile, interferometric phase compensation and rapid DEM geolocation also need to be considered in interferometric processing. In this paper, interferometric coherence was analyzed in detail, followed by an iterative filtering method, which helped to improve the interferometric performance. Further, a phase compensation method for Gaofen-3 was proposed to compensate for the phase error caused by the unsynchronized azimuth time offset of image pair, and a closed-form solution of DEM geolocation with ground control point (GCP) information was derived. Application of our methods to a pair of Gaofen-3 interferometric images showed that these methods were able to process the images with good accuracy and efficiency. Notably, these analysis and processing methods can also be applied to other SAR satellites in the ScanSAR mode to obtain DEMs with high quality.