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Downward continuation of airborne geomagnetic data based on two iterative regularization methods in the frequency domain 被引量:8
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作者 Liu Xiaogang Li Yingchun +1 位作者 Xiao Yun Guan Bin 《Geodesy and Geodynamics》 2015年第1期34-40,共7页
Downward continuation is a key step in processing airborne geomagnetic data. However,downward continuation is a typically ill-posed problem because its computation is unstable; thus, regularization methods are needed ... Downward continuation is a key step in processing airborne geomagnetic data. However,downward continuation is a typically ill-posed problem because its computation is unstable; thus, regularization methods are needed to realize effective continuation. According to the Poisson integral plane approximate relationship between observation and continuation data, the computation formulae combined with the fast Fourier transform(FFT)algorithm are transformed to a frequency domain for accelerating the computational speed. The iterative Tikhonov regularization method and the iterative Landweber regularization method are used in this paper to overcome instability and improve the precision of the results. The availability of these two iterative regularization methods in the frequency domain is validated by simulated geomagnetic data, and the continuation results show good precision. 展开更多
关键词 downward continuation Regularization parameter Iterative Tikhonov regularization method Iterative Landweber regularization metho
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High-precision downward continuation of potential fi elds algorithm utilizing adaptive damping coeffi cient of generalized minimal residuals 被引量:1
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作者 Zhang Zhi-Hou Liao Xiao-Long +6 位作者 Shi Ze-Yu Lowry Anthony R. Yao Yu Lu Run-Qi Fan Xiang-Tai Liu Peng-Fei Zhao Si-Wei 《Applied Geophysics》 SCIE CSCD 2020年第5期672-686,900,共16页
The downward continuation of potential fields is a process of calculating their values in a lower plane based on those of a certain plane.This technology is not only a data processing method for resource exploration b... The downward continuation of potential fields is a process of calculating their values in a lower plane based on those of a certain plane.This technology is not only a data processing method for resource exploration but also plays an extremely important role in military applications.However,the downward continuation of potential fields is a typical linear inverse problem that is ill-posed.Generalized minimal residuals(GMRES)is an eff ective solution to ill-posed inverse problems,but it is unstable under the condition wherein the GMRES is directly applied in the calculation process.Moreover,the long-term behavior of its iterative computation is a disordered,divergent result.Therefore,to obtain stable solutions,GMRES is applied to solve the normal equations of the downward continuation of potential fields;it is also used to prequalify for occasional interruptions in the operation process by adding the damping coefficient,thus strengthening the stability conditions of the equations of residual minimization.Finally,the stable downward continuation of the potential fields method is proposed.As indicated by the theoretical data and the measured testing data,the method proposed in this paper has the advantages of high-precision and excellent stability.Furthermore,compared with the Tikhonov iteration method,the proposed method avoids the need to choose regularization parameters. 展开更多
关键词 Potential fi elds generalized minimal residual method high precision and stable downward continuation
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Downward continuation of airborne gravimetry data based on Poisson integral iteration method 被引量:1
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作者 Xiaogang Liu Zhongmiao Sun +1 位作者 Kang Xu Mingda Ouyang 《Geodesy and Geodynamics》 2017年第4期273-277,共5页
The research and application of airborne gravimetry technology has become one of the hottest topics in gravity field in recent years. Downward continuation is one of the key steps in airborne gravimetry data processin... The research and application of airborne gravimetry technology has become one of the hottest topics in gravity field in recent years. Downward continuation is one of the key steps in airborne gravimetry data processing, and the quality of continuation results directly influence the further application of surveying data. The Poisson integral iteration method is proposed in this paper, and the modified Poisson integral discretization formulae are also introduced in the downward continuation of airborne gravimerty data. For the test area in this paper, compared with traditional Poisson integral discretization formula, the continuation result of modified formulae is improved by 10.8 mGal, and the precision of Poisson integral iteration method is in the same amplitude as modified formulae. So the Poisson integral iteration method can reduce the discretization error of Poisson integral formula effectively. Therefore, the research achievements in this paper can be applied directly in the data processing of our country's airborne scalar and vector gravimetry. 展开更多
关键词 Airborne gravimetry downward continuation Poisson integral Gravity anomaly Discretization
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Downward continuation of aeromagnetic data to the marine surface
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作者 XU Shizhe WANG Rui +2 位作者 ZHOU Jianxin XIAO Pengfei CHEN Shengchang 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2008年第1期54-60,共7页
The existing methods of downward continuation of potential field cannot be used to continue the aeromagnetic data to the marine surface because of the limited continuation distance. An iteration method for the downwar... The existing methods of downward continuation of potential field cannot be used to continue the aeromagnetic data to the marine surface because of the limited continuation distance. An iteration method for the downward continuation of potential field with a much larger continuation distance has been developed, which can continue the aeromagnetic data to the marine surface and get the marine - magnetic chart with the same scale as the aeromagnetic data. This downward continuation method will greatly raise the ef- ficiency of marine - magnetic investigation. The principle of the iteration method is presented. The method is demonstrated on synthetic models and real aeromagnetic data. Also, the error brought by continuation is discussed. The efficiency of the iteration method for the downward continuation of potential field is compared with the fast fourier transform (FFT) method, the former is much better than the latter. 展开更多
关键词 AEROMAGNETIC marine-magnetic downward continuation of potential field iteration method fast fourier transform
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Gravity Field Imaging by Continued Fraction Downward Continuation: A Case Study of the Nechako Basin(Canada)
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作者 ZHANG Chong ZHOU Wenna +1 位作者 LV Qingtian YAN Jiayong 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2021年第S01期102-105,共4页
Interpretation of gravity data plays an important role in the study of geologic structure and resource exploration in the deep part of the earth,like the lower crust,the upper mantle(Lüet al.,2013,2019).The gravi... Interpretation of gravity data plays an important role in the study of geologic structure and resource exploration in the deep part of the earth,like the lower crust,the upper mantle(Lüet al.,2013,2019).The gravity anomaly reflects the lateral resolution of the underground mass distribution. 展开更多
关键词 depth estimation downward continuation gravity data continued fraction
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A Continuous Downward Trend in Rents and Occupancy in 2009
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《Beijing Review》 2009年第13期35-35,共1页
Hong Kong took the top spot in the ranking of highest occupancy costs in the world,according to the
关键词 A Continuous downward Trend in Rents and Occupancy in 2009
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Multiscale Edge Analysis of Gravity Data and Its Applications
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作者 汪海洪 罗志才 宁津生 《Geo-Spatial Information Science》 2009年第3期230-234,共5页
In order to improve the processing and interpretation of gravity data, multiscale edge theory in image processing is introduced into the study of gravity field. Multiscale edges of gravity anomaly are analyzed based o... In order to improve the processing and interpretation of gravity data, multiscale edge theory in image processing is introduced into the study of gravity field. Multiscale edges of gravity anomaly are analyzed based on a special wavelet. It shows that the multiscale edges are the extrema points of the horizontal gravity gradient at different heights, which are related to the sharp discontinuities of underground sources. The applications of multiscale edge in downward continuation and gravity inversion are discussed. The simulated examples show that the multiscale edges can be applied to stabilize the downward continuation operator when the continuation height is low. The multiscale edges also have a convenient application to infer the geometry of the underground source. Moreover, the gravity inversion algorithm based on the multiscale edges has a good antinoise property. 展开更多
关键词 multiscale edge gravity anomaly downward continuation gravity inversion
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Sparing No Effort to Accelerate Private Investment Growth
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作者 Zhang Qizuo 《Beijing Review》 2016年第22期42-42,共1页
The Chinese economy has bottomed out and is stabilizing as economic growth remained within the reasonable range during the first four months of this year,judging by figures published by the National Bureau of Statisti... The Chinese economy has bottomed out and is stabilizing as economic growth remained within the reasonable range during the first four months of this year,judging by figures published by the National Bureau of Statistics.It is nonetheless alarming that private investment only increased by 5.2 percent during the same period,continuing a downward trend which had lasted for a long time. 展开更多
关键词 private continuing figures downward Bureau producer sector stabilizing innovative quarters
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