scholarly journals Pre-, co-, and post-rockslide analysis with ALOS/PALSAR imagery: a case study of the Jiweishan rockslide, China

2013 ◽  
Vol 1 (3) ◽  
pp. 1799-1822
Author(s):  
C. Zhao ◽  
Q. Zhang ◽  
Y. Yin ◽  
Z. Lu ◽  
C. Yang ◽  
...  
Keyword(s):  
Ground Deformation ◽  
Source Region ◽  
Intensity Change ◽  
Alos Palsar ◽  
Short Baseline ◽  
In Situ Data ◽  
Chongqing Municipality ◽  
Digital Elevation ◽  
Sar Imagery ◽  
Elevation Model

Abstract. On 5 June 2009, a catastrophic rockslide debris flow occurred at the crest of the Jiweishan range, Chongqing Municipality, China, killing 74 people and injuring an additional eight. We use L-band ALOS/PALSAR imagery to address landslide processes before, during and after the slide. We employ three different SAR methods, i.e. short baseline subsets (SBAS) interferometric SAR (InSAR), SAR backscattering intensity change, and InSAR stacking algorithm, to study any ground deformation before the rockslide, investigate the affected area, and calculate the topographic change by this slide, respectively. First, continuous deformation has been observed based on the available ALOS/PALSAR InSAR imagery during June and December 2007. Second, the area affected by the landslide can be inferred based on changes in SAR backscattering intensity as well as surface topography, with an estimated area of 0.47 million m2. Last, an InSAR-derived post-slide digital elevation model has allowed us to estimate surface height changes due to the slide, reaching about -80 m at the source region and about 60 m in the deposit region, respectively. Our InSAR-derived estimates have been validated using in-situ data and 3-D LiDAR measurements. The proposed procedures for rockslide analysis with satellite SAR imagery over a remote, mountainous, heavily vegetated region can be further extended to similar geo-hazards investigation and monitoring.

scholarly journals Pre-, co-, and post- rockslide analysis with ALOS/PALSAR imagery: a case study of the Jiweishan rockslide, China

2013 ◽  
Vol 13 (11) ◽  
pp. 2851-2861 ◽  
Author(s):  
C. Zhao ◽  
Q. Zhang ◽  
Y. Yin ◽  
Z. Lu ◽  
C. Yang ◽  
...  
Keyword(s):  
Ground Deformation ◽  
Source Region ◽  
Intensity Change ◽  
Alos Palsar ◽  
Short Baseline ◽  
In Situ Data ◽  
Chongqing Municipality ◽  
Digital Elevation ◽  
Elevation Model ◽  
Interferometric Sar

Abstract. On 5 June 2009, a catastrophic rockslide debris flow occurred at the crest of the Jiweishan range, Chongqing Municipality, China, killing 74 people and injuring an additional eight. We use L-band ALOS/PALSAR imagery to address landslide processes before, during and after the slide. We employ three different SAR methods, i.e., short baseline subsets (SBAS) interferometric SAR (InSAR), SAR backscattering intensity change, and InSAR stacking algorithm, to study any ground deformation before the rockslide, investigate the affected area, and calculate the topographic change by this slide, respectively. First, continuous deformation has been observed based on the available ALOS/PALSAR InSAR imagery during June and December 2007. Second, the area affected by the landslide can be inferred based on changes in SAR backscattering intensity as well as surface topography, with an estimated area of 0.47 million m2. Last, an InSAR-derived post-slide digital elevation model has allowed us to estimate surface height changes due to the slide, reaching about −80 m at the source region and about 60 m in the deposit region, respectively. Our InSAR-derived estimates have been validated using in situ data and 3-D lidar measurements.

Quality Assessment of Globally Available Digital Elevation Model (DEM) for Mountainous Region

2021 ◽  
Vol 5 (1) ◽  
pp. 11-21
Author(s):  
Sangay Gyeltshen ◽  
Krisha Kumar Subedi ◽  
Laylo Zaridinova Kamoliddinovna ◽  
Jigme Tenzin
Keyword(s):  
Digital Elevation Model ◽  
Vertical Displacement ◽  
Satellite System ◽  
Topographic Map ◽  
Alos Palsar ◽  
Aster Gdem ◽  
Digital Elevation ◽  
The Government ◽  
Elevation Model ◽  
The Individual

The study assessed the accuracies of globally available Digital Elevation Models (DEM’s) i.e., SRTM v3, ASTER GDEM v2 and ALOS PALSAR DEM with respect to Topo-DEM derived from topographic map of 5m contour interval. 100 ground control points of the elevation data were collected with the help of kinematic hand held GNSS (Global Navigation Satellite System), randomly distributed over the study area. The widely used RMSE statistic, NCC correlation and sub-pixel-based approach were applied to evaluate the erroneous, correlation, horizontal and vertical displacement in terms of pixels for the individual Digital Elevation Model. Following these evaluations, SRTM DEM was found to be highly accurate in terms of RMSE and displacement compared to other DEMs. This study is intended to provide the researchers, GIS specialists and the government agencies dealing with remote sensing and GIS, a basic clue on accuracy of the DEMs so that the best model can be selected for application on various purposes of the similar region.

scholarly journals Influência de lineamentos estruturais no desencadeamento dos movimentos de massa no maciço de Uruburetama, Ceará

2020 ◽  
Vol 13 (3) ◽  
pp. 1294
Author(s):  
Eduardo Viana Freires ◽  
Cláudio Ângelo da Silva Neto ◽  
Cynthia Romariz Duarte ◽  
César Ulisses Vieira Veríssimo ◽  
Daniel Dantas Moreira Gomes ◽  
...  
Keyword(s):  
High Energy ◽  
Automatic Extraction ◽  
Mass Movements ◽  
Alos Palsar ◽  
Geological Structures ◽  
Physical Conditions ◽  
Directional Filters ◽  
Digital Elevation ◽  
Predominant Orientation ◽  
Elevation Model

A disposição de estruturas geológicas em áreas planálticas é elemento importante na compreensão da dinâmica que ocorre na superfície de suas encostas e que é responsável pela esculturação do relevo. Neste contexto destacam-se os movimentos gravitacionais, que podem gerar perdas econômicas, ambientais e humanas em eventos de alta energia e/ou com grande extensão. Esta pesquisa analisou a influência de lineamentos estruturais no desencadeamento dos movimentos gravitacionais no maciço de Uruburetama, localizado no estado do Ceará. A metodologia consistiu na extração automática de lineamentos a partir do Modelo Digital de Elevação (MDE) fornecido pelo sensor orbital ALOS PALSAR. A partir da média de filtros direcionais aplicados a 0°, 45°, 90° e 135° de iluminação foi possível realçar as feições lineares da imagem original, facilitando sua extração. Posteriormente, foram elaborados mapas de distribuição espacial e densidade de lineamentos, além de diagrama de roseta. Tais produtos subsidiaram a análise da disposição dos principais trends estruturais da área, destacando que a maior densidade e a orientação predominante de lineamentos podem ser indicativas do grau de susceptibilidade à ocorrência de movimentos de massa no maciço de Uruburetama, desde que também sejam consideradas as características físicas dominantes e o grau de intervenção humana nas encostas. Os resultados demonstraram que os lineamentos estruturais obtidos de forma automática, quando analisados em conjunto com as características ambientais podem ser aplicados na análise de susceptibilidade à ocorrência de movimentos de massa.  Influence of structural lineaments as a trigger of mass movements in the Uruburetama massif, Ceará state, Brazil A B S T R A C TThe geological structures arrangement in plateau areas is an important element in understanding the dynamics that occur on the surface of their slopes and which is responsible for relief sculpting. In this context, gravitational movements stand out, which can generate economic, environmental and human losses in high energy events and / or with large extension. This research analyzed the influence of structural lineaments in the gravitational movements triggering in the Uruburetama massif, located in the state of Ceará. The methodology consisted of automatic extraction of lineaments from the Digital Elevation Model (DEM) provided by the ALOS PALSAR orbital sensor. From the average of directional filters applied at 0°, 45°, 90° and 135° of illumination it was possible to enhance the linear features of the original image, facilitating their extraction. Subsequently, maps of spatial distribution and lineaments density were developed, as well as a rosette diagram. Such products subsidized the analysis of the disposition of the main structural trends of the area, emphasizing that the higher density and the predominant orientation of lineaments may be indicative of the degree of susceptibility to the occurrence of mass movements in the Uruburetama massif, if the dominant physical conditions and the degree of human intervention on the slopes are also considered. The results showed that the structural lineaments obtained automatically, when analyzed together with the environmental characteristics can be applied in the susceptibility analysis to the occurrence of mass movements.Keywords: ALOS PALSAR, directional filters, image fusion, lineaments extraction

The potential of using Sentinel-1 and ALOS PALSAR-2 data for characterizing West Siberian lake ice backscatter anomalies

2021 ◽  
Author(s):  
Georg Pointner ◽  
Annett Bartsch
Keyword(s):  
Thick Layer ◽  
Arctic Lakes ◽  
The Arctic ◽  
Late Winter ◽  
Alos Palsar ◽  
Lake Ice ◽  
In Situ Data ◽  
L Band ◽  
Ice Regime ◽  
Sar Imagery

<p>Millions of lakes and ponds occupy large areas of the Arctic discontinuous and continuous permafrost zones. During most of the year, the surfaces of these lakes remain covered by a thick layer of ice. Synthetic Aperture Radar (SAR) data have shown to be useful for studying the ice on Arctic lakes, especially for monitoring lake ice phenology and the grounding state of the ice (ice frozen to the lakebed versus floating lake ice). Significant backscatter is often observed from the floating ice regime in C-band due to scattering on a rough ice-water interface.</p><p>Recent research has revealed features of anomalously low backscatter in Sentinel-1 C-band SAR imagery on some of the West Siberian lakes that likely belong to the floating ice regime. These anomalies are characterized by prominent shapes and sizes and seem to expand throughout late winter and/or spring. It is currently assumed that some of these features are related to strong emissions of natural gas (methane from hydrocarbon reservoirs), making it important to assess their origin in detail and understand the associated mechanisms. However, in-situ data are still missing.</p><p>Here, we assess the potential of the combined use of C-band Sentinel-1 (freely available) and L-band ALOS PALSAR-2 data  (available through JAXA PI agreement #3068002) to study the backscatter anomalies. We highlight the differences between observed backscatter from the two sensors with respect to different surface types (ground-fast lake ice, floating lake ice and anomalies) and investigate backscatter differences between frozen and melting conditions. Further, polarimetric classification is performed on L-band PALSAR-2 imagery, which reveals differences in scattering mechanisms between anomalies and floating lake ice.</p>

scholarly journals DEM Construction using DInSAR

2014 ◽  
Vol XL-8 ◽  
pp. 817-820 ◽  
Author(s):  
R. Mangla ◽  
S. Kumar
Keyword(s):  
Flash Flood ◽  
3D Visualization ◽  
Sar Interferometry ◽  
Atmospheric Effects ◽  
Alos Palsar ◽  
Digital Elevation ◽  
Temporal Decorrelation ◽  
Elevation Model ◽  
Differential Sar Interferometry ◽  
Differential Interferogram

A digital elevation model (DEM) is a 3D visualization of a terrain surface. It can be used in various analytical studies such as topographic feature extraction, hydrology, geomorphology and landslides analysis etc. Uttrakhand region is affected with landslides, earthquake and flash flood phenomenon. Hence this study was focused on DEM generation using Differential SAR Interferometry (DINSAR) on ALOS PALSAR dataset. Two Pass DINSAR technique involves one interferometric pair in addition with an external DEM. The external DEM was used as a reference to reduce topographic errors. The data processing steps were image co-registration, interferogram generation, interferogram flattening (Differential Interferogram), interferogram filtering, coherence map, phase unwrapping, orbital refinement and re-flattening and DEM generation. Interferogram fringes observed in forest areas were due to temporal decorrelation and the fringes in mountain regions were obtained due to topography changes (may be due to landslides in rainy season). The range of elevation in generated DEM were 132 m to 2823 m and Root Mean Square Error (RMSE) error was 36.765159 m. The generated DEM was compared with ASTER DEM and variation in height was analyzed. Atmospheric effects were not removed due to geometrical and temporal decorrelation which affect the accuracy.

Flood Monitoring Using ERS-1 SAR Imagery and Digital Elevation Model

1998 ◽  
Vol 31 (12) ◽  
pp. 67-73
Author(s):  
Th. Alexandridis ◽  
K. Perakis ◽  
N. SiIleos
Keyword(s):  
Digital Elevation Model ◽  
Digital Elevation ◽  
Flood Monitoring ◽  
Sar Imagery ◽  
Elevation Model

scholarly journals IGS-CMAES: A Two-Stage Optimization for Ground Deformation and DEM Error Estimation in Time Series InSAR Data

2021 ◽  
Vol 13 (13) ◽  
pp. 2615
Author(s):  
Xinyao Sun ◽  
Aaron Zimmer ◽  
Subhayan Mukherjee ◽  
Parwant Ghuman ◽  
Irene Cheng
Keyword(s):  
Time Series ◽  
Time Series Data ◽  
Optimization Problems ◽  
Ground Deformation ◽  
Series Data ◽  
Two Stage ◽  
Real Time Processing ◽  
Sensing Technology ◽  
Digital Elevation ◽  
Elevation Model

Interferometric synthetic aperture radar (InSAR) has become an increasingly recognized remote sensing technology for earth surface monitoring. Slow and subtle terrain displacements can be estimated using time-series InSAR (TSInSAR) data. However, a substantial increase in the availability of exclusive time series data necessitates the development of more efficient and effective algorithms. Research in these areas is usually carried out by solving complicated optimization problems, which is very computationally expensive and time-consuming. This work proposes a two-stage black-box optimization framework to jointly estimate the average ground deformation rate and terrain digital elevation model (DEM) error. The method performs an iterative grid search (IGS) to acquire coarse candidate solutions, and then a covariance matrix adaptive evolution strategy (CMAES) is adopted to obtain the final local results. The performance of our method is evaluated using both simulated and real datasets. Both quantitative and qualitative comparisons using different optimizers support the reliability and effectiveness of our work. The proposed IGS-CMAES achieves higher accuracy with a significantly fewer number of objective function evaluations than other established algorithms. It offers the possibility for wide-area monitoring, where high precision and real-time processing is essential.

scholarly journals Konversi DSM Menjadi DTM Menggunakan Filter Berbasis Kelerengan Untuk Pemetaan Genangan Banjir Rob Di Kecamatan Tirto

2020 ◽  
Author(s):  
Trida Ridho Fariz ◽  
Nur Rokhayati
Keyword(s):  
Digital Terrain Model ◽  
Surface Model ◽  
Digital Surface Model ◽  
Model Data ◽  
Alos Palsar ◽  
Terrain Model ◽  
Digital Terrain ◽  
Digital Elevation ◽  
Elevation Model ◽  
Digital Elevation Model Data

Salah satu data penginderaan jauh yang penting adalah DEM (Digital Elevation Model). Data DEM memberikan informasi ketinggian suatu permukaan bumi dimana dikelompokkan menjadi 2 yaitu DSM (Digital Surface Model) yang menyajikan informasi ketinggian permukaan tutupan lahan dan DTM (Digital Terrain Model) yang menyajikan informasi ketinggian tanah. Pemetaan banjir rob secara umum menggunakan data DTM. Tetapi untuk mendapatkan data DTM sangatlah sulit. Salah satu data DEM yang tersedia secara gratis adalah data DEM terkoreksi hasil ekstraksi dari ALOS PALSAR yang memiliki resolusi spasial 12,5 meter, tidak terlalu bagus untuk digunakan sebagai data untuk pemetaan genangan banjir rob mengingat itu hanyalah DSM. Sedangkan menggunakan data titik ketinggian yang di interpolasi tidak terlalu merepresentatifkan kondisi ketinggian medan suatu wilayah kecuali jika jumlah titiknya banyak. Penelitian ini menggunakan metode slope based filtering untuk mengkonversi data DEM dari ALOS PALSAR menjadi DTM.Hasil dari metode ini dilakukan uji statistik berupa korelasi dengan data titik ketinggian dan mempunyai nilai korelasi yang sangat tinggi yaitu sebesar 0,80 dan nilai RMSE sebesar 1,402. Selanjutnya dibuat pemodalan spasial genangan banjir rob dari DTM. Hasil pemodelan spasial genanngan banjir rob kemudin diuji akurasi dengan uji statistik korelasi dan penghitungan RMSE dengan data hasil survey lapangan. Hasil pemodelan memiliki korelasi sebesar 0,78 dengan nilai RMSE tinggi genangan banjir rob sebesar 0,763. Yang berarti bahwa rata-rata selisih nilai ketinggian genangan banjir rob dari peta dan dilapangan adalah sebesar 0,763m. Wilayah genangan banjir rob meliputi Desa Jeruksari, Desa Tegaldowo, Desa Mulyorejo dan Desa Karangjompo.

Monitoring Ground Deformation Using Extracted DEM from Stereo-Pair Images of ALOS/PRISM

2012 ◽  
Vol 229-231 ◽  
pp. 1377-1380
Author(s):  
Jing Guo Lv ◽  
De He Yang ◽  
Feng Yuan ◽  
Ming Hui Yang
Keyword(s):  
Land Subsidence ◽  
Ground Deformation ◽  
Deformation Monitoring ◽  
The Other ◽  
Stereo Pair ◽  
Digital Elevation ◽  
Elevation Model ◽  
Automatic Matching ◽  
And Control ◽  
Alos Prism

This paper used high resolution stereo-pair images from PRISM of Advanced Land Observing Satellite to generate high precision digital elevation model of target areas, which adopts the method of object space automatic matching and control detection. Compared with the same resolution of DEM from the other way in the same area, the paper educes the area of land subsidence and changed trend and analyzes the factors of accuracy for building DEM. The New DEM has higher precision than the standard DEM and reflects the real geomorphology. Through the experimental statistical analysis, the proposed method can be used for large areas of land subsidence and deformation monitoring, which is timeliness to explore reasons of region deformation.

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