Geophysical Survey

About: Geophysical Survey is a facility organization based out in Obninsk, Russia. It is known for research contribution in the topics: Geology & Seismology. The organization has 308 authors who have published 256 publications receiving 3067 citations. The organization is also known as: Federal State Institution of Science Geophysical Survey of the Siberian Branch of the Russian Academy of Sciences.

Monitoring Subsidence in Tianjin Area Using the Multi-Baseline D-InSAR Technique

Abstract: Subsidence has been affecting Tianjin since 1960s. It posed comprehensive detrimental effects on natural environment, the economy and society. Considering the actual monitoring demand for land subsidence in Tianjin area, multi-baseline D-InSAR technique was studied. Using the multi-baseline DInSAR technique more interferograms can be generated, which is useful for retrieving the subsidence velocity accurately. And then regression algorithm and least square method are used to deal with the time series to get deformation result. In this paper, the multi-baseline DInSAR technique is used to measure the subsidence velocity in Tianjin area. It can be concluded that the algorithm is effective and feasible especially in the study area.

Seismotectonic Deformations of the Kuril Island Arc during Different Phases of the Seismic Cycle: The Simushir Earthquakes

Abstract: Multiyear satellite geodetic measurements along the Kuril island arc provided data for studying the condition of the Benioff seismic zone and the occurrence of various deformation mechanisms that are responsible for surface displacements. Factors have been determined whose combination can explain the diverse character of observed movements: space–time variations in interplate sliding, viscoelastic postseismic relaxation in the asthenosphere, stationary backward mantle flow, the keyboard structure of the frontal part of the subduction zone. The stationary displacement components have been detected against the background of transient processes. These components can be associated with interplate coupling and sublithospheric currents and they can be employed in order to characterize the interseismic condition of various parts along the Kuril isalnd arc. In particular, the special character of seismicity in the Middle Kuril area, which consists in long intervals of seismic quiescence interrupted by large double earthquakes, can be caused by a zone of hypothetical transition from strong interplate coupling in the southwest to poor coupling combined with a backward sublithospheric current in the northeast.

Estimation of shie glacier surface movement using offset tracking technique with cosmo-skymed images

Abstract: . Movement is one of the most important characteristics of glaciers which can cause serious natural disasters. For this reason, monitoring this massive blocks is a crucial task. Synthetic Aperture Radar (SAR) can operate all day in any weather conditions and the images acquired by SAR contain intensity and phase information, which are irreplaceable advantages in monitoring the surface movement of glaciers. Moreover, a variety of techniques like DInSAR and offset tracking, based on the information of SAR images, could be applied to measure the movement. Sangwang lake, a glacial lake in the Himalayas, has great potentially danger of outburst. Shie glacier is situated at the upstream of the Sangwang lake. Hence, it is significant to monitor Shie glacier surface movement to assess the risk of outburst. In this paper, 6 high resolution COSMO-SkyMed images spanning from August to December, 2016 are applied with offset tracking technique to estimate the surface movement of Shie glacier. The maximum velocity of Shie glacier surface movement is 51 cm/d, which was observed at the end of glacier tongue, and the velocity is correlated with the change of elevation. Moreover, the glacier surface movement in summer is faster than in winter and the velocity decreases as the local temperature decreases. Based on the above conclusions, the glacier may break off at the end of tongue in the near future. The movement results extracted in this paper also illustrate the advantages of high resolution SAR images in monitoring the surface movement of small glaciers.

Study of modified band selection methods of hyperspectral image based on optimum index factor

Abstract: As hyperspectral remote sensing image have the features of high spectral resolution, high dimension, it brings a serious problem of choosing the appropriate band combination from numerous bands. To solve the problem，the present paper, basing on Optimum Index Factor, proposes a modified band selection algorithm. It aims to reduce the dimension through the improved block adaptive band selection. According to the strong correlation among the bands of hyperspectral remote sensing image，the paper introduces hyperspectral band selection method based on the correlation between bands. The modified algorithm can overcome some shortages of Optimum Index Factor, such as inefficient of selecting bands. However, it can also remain some characteristics from Optimum Index Factor. For instance, the selected band combination, through the modified algorithm, can retain rich amount of information and weak correlation between the selected bands. And the compute complication is decreased rapidly. Taking Hyperion hyperspectral remote sensing image from EarthObserving-1 as example, the present paper contrast the practical effect of the modified algorithm of sub regional selection band and Optimum Index Factor.