Linear discontinuous ground deformation detection based on coherence analysis of pre and post event radar image pairs

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Bartosz Apanowicz

Abstract The article presents information on how to use satellite interferometry to detect linear discontinuous ground deformation [LDGD] caused by underground mining. Assumptions were made based on the properties of the SAR signal correlation coefficient (coherence). Places of LDGD have been identified based on these assumptions. Changes taking place on the surface between two acquisitions lead to worse correlation between two radar images. This results in lower values of the SAR signal correlation coefficient in the coherence maps. Therefore, it was assumed that the formation of LDGD could reduce the coherence value compared to the previous state. The second assumption was an increase in the standard deviation of coherence, which is a classic measurement of variability. Therefore any changes in the surface should lead to increasing standard deviation of coherence compared to the previous state. Images from the Sentinel-1 satellite and provided by the ESA were used for analysis. The research is presented on the basis of two research areas located in the Upper Silesian Coal Basin in the south of Poland. The area in which LDGD could occur was limited to 6 % of the total area in case 1 and 36 % in case 2 by applying an appropriate methodology of satellite image coherence analysis. This paper is an introduction to the development of a method of detecting LDGDs caused by underground mining and to study these issues further.

2021 ◽  
Author(s):  
Davide Festa ◽  
Pierluigi Confuorto ◽  
Matteo Del Soldato ◽  
Silvia Bianchini ◽  
Nicola Casagli

<p>The launch of the Sentinel-1 constellation by the European Copernicus Program, primarily devoted to scientific community research, has allowed acquiring huge volumes of radar images with worldwide coverage and a short temporal sampling (12 days reduced to 6 days thanks to their position at 180° in the same orbit). The systematic collection of imagery and the repeated processing of each new pair of images acquired opened the unprecedent possibility of conducting a continuous monitoring of Earth surface deformations, such as subsidence and slope instabilities over different geomorphological settings. At present, Tuscany, Veneto and Valle d’Aosta regions (Italy) are benefiting from systematical Sentinel-1-based monitoring of geological and geomorphological hazards. The promising outcomes so far obtained constitute a decisive step towards near-real-time monitoring and therefore a valid support for geohazard risk management activities. Retracing the pattern set by the encouraging results from the three Italian Regions, an operating workflow chain is proposed in the framework of an operational monitoring service, from the collection of satellite images to the possibility of conducting field surveys. The procedure is based on 4 different steps: i) continuous collection of Sentinel-1 images, constant data processing through an MT-InSAR (Multi-Temporal Interferometric Synthetic Aperture Radar) technique and exploitation of a data-mining algorithm able to retain only meaningful Measurement Points (MP) in terms of abrupt change of displacement rate; ii) radar-interpretation of the filtered MP for the detection of the possible causes of the anomalies through the use of ancillary informative layers or pre-existing databases; iii) dissemination of the relevant radar-interpreted information to hydrological risk managing actors by a direct alert or periodic bulletins; iv) field investigation, preliminary risk assessment and possible remedial works design. The procedure was successfully applied gathering evidence of its usefulness in practical terms. The cases of the Bosmatto landslide (Valle d’Aosta Region) and the case of the Zeri Landslide (Tuscany Region) which belong to two alpine and apennine environments, respectively, are reported. In the first example, in response to a relevant acceleration interpreted from the MP available on the area of interest, an alert was sent to the regional officers who increased their awareness related to the risk posed by the Bosmatto Landslide. In the second example, a monitoring bulletin which is periodically delivered for the Tuscany Region pointed out the meaningfulness and persistency of anomalies identified in the Zeri municipality. This led the regional authorities to conduct a site investigation oriented to the assessment of preliminary risks. The presented results highlight the effective benefits-cost ratio, the high precision and the short amount of time required to complete the procedure representing a best practice for the early detection of ground deformation events.</p>


2018 ◽  
Vol 29 (6) ◽  
pp. 585-592 ◽  
Author(s):  
Ana B Plaza-Puche ◽  
Liberdade C Salerno ◽  
Francesco Versaci ◽  
Daniel Romero ◽  
Jorge L Alio

Purpose:To evaluate the intrasubject repeatability of the ocular aberrometry obtained with a new ocular pyramidal aberrometer technology in a sample of normal eyes.Methods:A total of 53 healthy eyes of 53 subjects with ages ranging from 18 to 45 years were included in this study. In all cases, three consecutive acquisitions were obtained. Intrasubject repeatability of the measurements with a pyramidal aberrometer was calculated. Intrasubject repeatability for 4.0- and 6.0-mm pupils was evaluated within the subject standard deviation (Sw) and intraclass correlation coefficient.Results:Low values of the Swand intraclass correlation coefficient outcomes close to 1 were observed for the sphere and cylinder at 3.0-mm pupil size. Most low Swand intraclass correlation coefficient values close to 1 were observed for total, low-order aberrations and higher-order aberrations root mean square and for each Zernike coefficient analysis (intraclass correlation coefficient ⩾0.798) at 4.0-mm pupil size, with more limited outcomes for the aberrometric coefficient of Z(4, 4) with an intraclass correlation coefficient of 0.683. For a 6.0 mm pupil diameter, low Swand intraclass correlation coefficient values close to 1 were observed for all aberrometric parameters or Zernike coefficients analyzed (intraclass correlation coefficient ⩾0.850).Conclusion:The new pyramidal aberrometer Osiris provides repeatable and consistent measurements of ocular aberrometry measurements in normal eyes.


2017 ◽  
Vol 1 (3) ◽  
pp. 71-101
Author(s):  
Amela Mohsen Naji ◽  
Aziz Saleh Salman Al - Baaj

The study aims to demonstrate the importance of training and development to improve the corporate image in the minds of customers, and impact analysis and correlation of training and development in the image of the company, and the study was conducted in two rational and Assyria, the formations and the Ministry of Construction and Housing and public municipalities, and adopted the questionnaire as a tool for the study, which distributed 105 identification of the respondents the two companies were retrieving 83 questionnaire and ruled out a number 2 questionnaire for non-compliance with the conditions, bringing to the total number of sample 81 Mbhotha. "were used in the study statistical methods percentage, the arithmetic mean is likely, the standard deviation, the relative importance, ratios correlation coefficient (Spearman) F test, Spss program and coefficient of determination R2%, it found a number of conclusions of the most important interest of the two companies are actively training and development Alambhottin with weakness in the support of the trainees before, during and after the training process, and finally the study came out a set of recommendations including the provision of adequate support by the management of the trainees before, during and after the training process and the need to increase interest in actively training and development for workers being reflected positively on the mental image of the company among customers.


Author(s):  
Arindam Majumder ◽  
Abhishek Majumder

Multi-objective optimization is one of the most popular research areas in the world of manufacturing. It concerns the manufacturing optimization problems involving more than one optimization simultaneously, but in this present scenario, it is becoming very tough to solve a manufacturing-related multi-objective problem as no logical method has been developed in assignment of response individual weight. Therefore, to tackle this problem, this chapter proposes a new integrated approach by combining Standard Deviation Method with Particle Swarm Optimization. Two examples of optimizing the advanced manufacturing process parameters are performed to test the proposed approach. The examples considered for this approach are also attempted using other established optimization techniques such as Desirability-based RSM and SDM-GA. The results verify the effectiveness of the proposed approach during multi-objective manufacturing process parameter optimization.


1983 ◽  
Vol 104 ◽  
pp. 185-186
Author(s):  
M. Kalinkov ◽  
K. Stavrev ◽  
I. Kuneva

An attempt is made to establish the membership of Abell clusters in superclusters of galaxies. The relation is used to calibrate the distances to the clusters of galaxies with two redshift estimates. One is m10, the magnitude of the ten-ranked galaxy, and the other is the “mean population,” P, defined by: where p = 40, 65, 105 … galaxies for richness groups 0, 1, 2 …, and r is the apparent radius in degrees given by: The first iteration for redshift, z1, is obtained from m10 alone: The standard deviation for Eq. (1) is 0.105, the number of clusters with known velocities is 342 and the correlation coefficient between observed and fitted values is 0.921. With zi from Eq. (1), we define Cartesian galactic coordinates Xi = Rih−1 cosBi cosLi, Yi = Rih−1 cosBi sinLi, Zi = Rih−1 sinBi for each Abell cluster, i = 1, …, 2712, where Ri is the distance to the cluster (Mpc), and Ho = 100 h km s−1 Mpc−1.


2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Li Wen ◽  
Qing Li ◽  
Wei Li ◽  
Qiao Cai ◽  
Yong-Ming Cai

Hydroxyl benzoic esters are preservative, being widely used in food, medicine, and cosmetics. To explore the relationship between the molecular structure and antibacterial activity of these compounds and predict the compounds with similar structures, Quantitative Structure-Activity Relationship (QSAR) models of 25 kinds of hydroxyl benzoic esters with the quantum chemical parameters and molecular connectivity indexes are built based on support vector machine (SVM) by using R language. The External Standard Deviation Error of Prediction (SDEPext), fitting correlation coefficient (R2), and leave-one-out cross-validation (Q2LOO) are used to value the reliability, stability, and predictive ability of models. The results show that R2 and Q2LOO of 4 kinds of nonlinear models are more than 0.6 and SDEPext is 0.213, 0.222, 0.189, and 0.218, respectively. Compared with the multiple linear regression (MLR) model (R2=0.421, RSD = 0.260), the correlation coefficient and the standard deviation are both better than MLR. The reliability, stability, robustness, and external predictive ability of models are good, particularly of the model of linear kernel function and eps-regression type. This model can predict the antimicrobial activity of the compounds with similar structure in the applicability domain.


2019 ◽  
Vol 11 (5) ◽  
pp. 584 ◽  
Author(s):  
Qin Peng ◽  
Shuanggen Jin

The significant wave height (SWH) of the sea is an important parameter and plays an important role in the prediction of waves and ocean dynamics. However, traditional methods, e.g., buoys or traditional remote sensing techniques such as X-band radar image have small measurement range and high cost. Recently, Global Navigation Satellite System-Reflectometry (GNSS-R) has provided a new opportunity to estimate the SWH, especially the space-borne Cyclone-GNSS (CYGNSS) launched on December 15, 2016. The GNSS-R uses the GNSS-reflected signal received by the receiver to invert ground physical parameters with all-weather, global fast coverage, high resolution, high precision, high long-term stability, rich signal sources, passive detection, and strong concealment. In this paper, the global ocean significant wave height is estimated using space-borne CYGNSS GNSS-R data for the first time though the relationship between the square root of the signal-to-noise ratio (SNR) data of CYGNSS delayed Doppler map (DDM) and the SWH. Then, the estimated significant wave height is compared with the satellite altimeter and buoy data. Compared with the AVISO SWH observation, the standard deviation value reaches 0.3080 m and the correlation coefficient reaches 0.9473 m. The correlation coefficient with the buoy SWH observation is 0.9539 m and the standard deviation is 0.2761 m. The SWH estimations from CYGNSS can provide important support in ocean shipping development, marine environmental protection, marine disaster warning and forecasting.


2011 ◽  
Vol 383-390 ◽  
pp. 2201-2205
Author(s):  
Xin Xi Liu ◽  
Xue Zhi Wang

Analysis on the characters of ground subsidence of Yangjiaping mining area, with same excavation depth and recovery coefficient, the numerical simulations to nonlinear large deformation using finite-difference method(FLAC) are achieved on the different strip extraction schemes that adopted different mining and reservation width. The result indicates that the subsidence values and horizontal deformation increases with the increasing of the strip extraction width on condition of the same recovery rate. Based on probability density function (PDF) method, the relationship of the coal pillar width, the mining width and ground deformation is acquired, which is some useful reference for using the strip extraction method to control the surface movement and deformation.


1973 ◽  
Vol 51 (9) ◽  
pp. 1363-1367 ◽  
Author(s):  
P. J. Krueger

The fundamental carbonyl stretching frequencies for o-, m-, and p-substituted acetophenones in dilute CCl4 solution are correlated with the electrophilic substituent constant σ+ by the expression vc=o (cm−1) = 11.53σ+ + 1691.5 (n = 27, correlation coefficient = 0.988, standard deviation = 1.2 cm−1). The frequencies of carbonyl groups trans to an o-substituent follow this correlation, assuming σo+ ≈ σp+, while those oriented cis to the substituent generally do not. Deviations from this correlation are interpreted in terms of dipole–dipole interactions, steric hindrance to planarity, intramolecular hydrogen bonding, and non-additivity of σ+ values for some combinations of substituents. The carbonyl frequencies for singly m- and p-substituted acetophenones are also correlated with the polar and resonance components of σ+ by the expression vc=o (cm−1) = 15.66σI + 10.99σR+ + 1689.8 (n = 13, correlation coefficient = 0.981, standard deviation = 0.9 cm−1). Thus the sensitivity of the carbonyl frequency to the polar effect is greater than to the resonance effect. In ω-substituted acetophenones no precise correlation with polar substituent constants is observed.


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