Accuracy Of Deformation Monitoring Research Articles

Using the typification of mining-engineering facilities to substantiate deformation monitoring of opencast mining

To date, in the field of monitoring deformations of the earth’s surface in the area of opencast mining, there is almost no current regulatory and methodological documentation that regulates the conduct of observations and at the same time takes into account the features of existing mining facilities of opencast mining and the possibilities of modern survey technologies. The paper gives an approach to determining a set of methods for deformation monitoring within the territory of mining enterprises engaged in open-pit mining, based on the results of the typification of mining facilities. The developed typification makes it possible to estimate the degree of complexity of mining-engineering facilities, taking into account their size, features of engineering-geological, hydrogeological and orographic conditions, geodynamic processes. To increase the information content of mine surveying, as well as the quality and accuracy of deformation monitoring as a whole, it is proposed to include technologies for Earth remote sensing from space, namely, satellite-based synthetic aperture radar (SAR) interferometry, used within the proposed concept for areal monitoring of deformations and detection potentially hazardous areas at complex and particularly complex opencast mining facilities. The proposed approach to the organization of deformation monitoring was tested within the territory of the Khibiny apatite-nepheline deposit of the Rasvumchorr Plateau: the complexity of conditions for the development of the Tsentralny open pit was evaluated and recommendations were formulated for conducting mine surveying of deformations of the earth’s surface in its territory using satellite-based SAR interferometry. This method was used to analyze deformations of the earth’s surface for the periods from 2007 to 2011 and from 2015 to 2016 according to data from the ALOS PALSAR, TerraSAR-X and Sentinel-1 satellites.

Deformation information extraction method based on differential synthetic aperture radar interferometry

As aerospace technology, computer technology, network communication technology and information technology become more and more perfect, a variety of sensors for measurement and remote sensing are constantly emerging, and the ability to acquire remote sensing data is also continuously enhanced. Synthetic Aperture Radar Interferometry (InSAR) technology greatly expands the function and application field of imaging radar. Differential InSAR (DInSAR) developed based on InSAR technology has the advantages of high precision and all-weather compared with traditional measurement methods. However, DInSAR-based deformation monitoring is susceptible to spatiotemporal coherence, orbital errors, atmospheric delays, and elevation errors. Since phase noise is the main error of InSAR, to determine the appropriate filtering parameters, an iterative adaptive filtering method for interferogram is proposed. For the limitation of conventional DInSAR, to improve the accuracy of deformation monitoring as much as possible, this paper proposes a deformation modeling based on ridge estimation and regularization as a constraint condition, and introduces a variance component estimation to optimize the deformation results. The simulation experiment of the iterative adaptive filtering method and the deformation modeling proposed in this paper shows that the deformation information extraction method based on differential synthetic aperture radar has high precision and feasibility.

Assessing the Use of GACOS Products for SBAS-InSAR Deformation Monitoring: A Case in Southern California.

The Generic Atmospheric Correction Online Service (GACOS) products for interferometric synthetic aperture radar (InSAR) are widely used near-real-time and global-coverage atmospheric delay products which provide a new approach for the atmospheric correction of repeat-pass InSAR. However, it has not been determined whether these products can improve the accuracy of InSAR deformation monitoring. In this paper, GACOS products were used to correct atmospheric errors in short baseline subset (SBAS)-InSAR. Southern California in the U.S. was selected as the research area, and the effect of GACOS-based SBAS-InSAR was analyzed by comparing with classical SBAS-InSAR results and external global positioning system (GPS) data. The results showed that the accuracy of deformation monitoring was improved in the whole study area after GACOS correction, and the mean square error decreased from 0.34 cm/a to 0.31 cm/a. The improvement of the mid-altitude (15–140 m) point was the most obvious after GACOS correction, and the accuracy was increased by about 23%. The accuracy for low- and high-altitude areas was roughly equal and there was no significant improvement. Additionally, GACOS correction may increase the error for some points, which may be related to the low accuracy of GACOS turbulence data.

Semi-automatic selection of optimum image pairs based on the interferometric coherence for time series SAR interferometry

ABSTRACTTime series synthetic aperture radar (SAR) interferometry (TS-InSAR) has been widely used for monitoring ground deformation. The selection of interferometric image pairs directly affects the quality of the interferograms and the accuracy of deformation monitoring. The Small BAseline Subset (SBAS) method has been widely adopted to form interferograms in TS-InSAR. However, the selection of low-quality interferograms or missed selection of good interferograms due to temporal and/or spatial baselines exceeding the thresholds sometimes occurs in the traditional SBAS method. This letter proposes a new method, namely, the semi-automatic selection of optimum image pairs (SASOIP), based on the interferometric coherence. By quantitatively evaluating the coherence of point targets in a small feature region, the SASOIP results in high-quality interferometric image pairs selected from all possible interferometric combinations for any two SAR images. The SASOIP method can effectively reduce the probability of poor selection and missed selection of quality image pairs. Twenty-nine COSMO-SkyMed SAR images acquired from 27 August 2011, to 29 July 2015, over Tianjin, China, are used to test the proposed algorithm. Validation with 102 levelling data points demonstrates that the accuracy of ground deformation derived from the interferograms by the SASOIP method is 23.13% higher than that based on the SBAS method.

Deformation Monitoring for Subway Tunnels Based on TLS

The paper studies Terrestrial Laser Scanning used in subway tunnel deformation monitoring. For special narrow subway tunnel structure, the accumulated error between the adjacent station can be eliminated by global registration pattern which is to set the common control point within the section ends. Point cloud slicing is used to calculate the radius of the circle by multi-point coordinate, deformation is fitted to curve to show the monitoring result by analyzing the center coordinates sequence trends and mean curvature. Three-dimensional model of subway tunnel not only improves the accuracy of deformation monitoring, but also reflects the overall deformation trend. This method is applied to monitor deformation for Shanghai Metro Line twelve, comparing with the total station method, high precision of deformation monitoring meet the need.