A rapid mapping of landslides following a disaster is important for coordinating emergency response and limiting rescue delays. synthetic aperture radar (SAR) can provide solution even in harsh weather at night, due to its independence light, quick response, no contact broad coverage. This study aimed conduct comprehensive exploration on the intensity coherence information three Advanced Land Observing Satellite-2 (ALOS-2) SAR images, massive landslide pixel level, order reference future...

Summary Viscoelastic (VE) dampers, composed of VE layers sandwiched between relative rigid steel plates, have been widely used as dissipation devices to improve performance structures under dynamic loads. Corresponding analytical and experimental investigations carried out by many scholars. However, most dampers studied before are typically traditional applied in regular structures. This paper introduces a new type damper with strong nonlinearity the complex irregular structure Nanjing...

When carrying out change detection for building damage assessment using synthetic aperture radar (SAR) intensity images, it is desirable that the observation conditions of images are similar and acquisition time close to earthquake occurrence time. In this way, influence operating system ground temporal changes can be minimized, facilitating high-accuracy results. However, in practice, especially poor developing areas, difficult obtain ideal owing limited pre-event data archives. 2015...

Summary Incremental dynamic analysis (IDA) is a useful method in performance‐based earthquake engineering. IDA curves combine the intensity measure (IM) of ground motions with structural responses (as measured by engineering demand parameter) from nonlinear analysis. However, display large record‐to‐record variability. And various IMs can lead to different results. Therefore, it important find desirable IM reduce discreteness So far, studies on for have been carried out many scholars...

The Persistent Scatterer Interferometry (PSI) analysis accurately estimates the change over time of only PS points on ground surfaces using variation phase pixels with a small amount noise called Scatter (PS).The riprap external surface rockfill dam is well reflected by radar, and since many can be obtained entire dam, deformation grasped in planar manner. In this paper, PSI was conducted for six large-scale dams TEPCO Renewable Power SAR (Synthetic Aperture Radar) data from Sentinel-1...

近年,人工衛星SARデータの活用については社会インフラ設備の維持管理などへの研究が進んでいるものの,恒久散乱点が得られやすいロックフィルダムにおいても,PSInSAR解析による恒久散乱点の変位の計測精度が十分に検証されているとは言い難い.本論文では,既に安定期にあるもののここ数年でも年間最大1cm程度変位しており,外部変形量を連続計測しているロックフィルダムを対象に,Sentinel-1 SARデータを活用したPSInSAR解析を実施し,測量値と解析結果を比較することにより,人工衛星SARデータから把握できる変位の精度を検証するとともに,ロックフィルダムの保守管理への適用性について考察した.ロックフィルダム外部変形の測量値と解析結果の比較により,PSInSAR解析によりmmオーダーの高い精度で計測できることが検証され,保守管理に人工衛星SARデータが活用できる可能性があることを示した.

A PSInSAR analysis utilizing Sentinel-1 SAR data was conducted for a rockfill dam, which is already in the stabilization phase but has been deformed by up to about 10 mm per year past several years and external deformation continuously measured, verify accuracy of displacement that can be determined from satellite comparing results with survey data. The provides many PS points on entire outer surface dam. It verifies measured accurately order using Senttenel-1 data, indicating used manage dams.

Permanent scattering points can be measured with high accuracy and are rarely obtained by PSInSAR analysis on slopes few artificial structures, such as mountainous areas. Installing a corner reflector at the target point makes that permanent enables highly accurate measurements. In this paper, measurement of installation position is verified installing forced to displace comparing displacement PS actual from using Sentinel-1 SAR data. Small cost-effective reflectors were installed for slope...

Sentinel-1 SARデータを用いて,積雪深の推定方法を検討するとともに,群馬県の利根川最上流域を対象に,積雪深観測所での観測値を用いてその推定精度を検証した.本地域の森林地帯において,積雪深と斜面のVV偏波とVH偏波の後方散乱係数の関係性について検討した結果,後方散乱係数から積雪深の推定が可能であることを確認した.木が生い茂っている500m四方の斜面の後方散乱係数から4m以下の積雪深の推定精度は,推定条件などによるが20~50cm程度となり,融雪量推定のための広域な流域面積での積雪の状況を把握することなどに活用できる可能性がある.

A method for estimating snow depth using Sentinel-1 SAR data was investigated, and its estimation accuracy verified observations at a station in heavy snowfall area Niigata Prefecture, Japan. relation observed between the backscatter coefficients of VV VH polarizations, flat fields even slopes covered with trees, it confirmed that could be estimated from coefficients. The observatory is about 20 cm, which used to determine cover over wide catchment amount snowmelt.