One-step compensation downward continuation method free of iteration in wave number domain

2020 ◽  
Vol 55 (2) ◽  
pp. 163-181
Author(s):  
Yu Huang ◽  
Zhenchuan Lv ◽  
Lihua Wu
2020 ◽  
Vol 7 (10) ◽  
Author(s):  
Yuan Yuan ◽  
Wenna Zhou ◽  
Xiangyu Zhang ◽  
Guochao Wu ◽  
Shuiliang Tang ◽  
...  

Author(s):  
Kha Van Tran ◽  
Trung Nhu Nguyen

Summary Downward continuation is a very useful technique in the interpretation of potential field data. It would enhance the short wavelength of the gravity anomalies or accentuate the details of the source distribution. Taylor series expansion method has been proposed to be one of the best downward continued methods. However, the method using high-order vertical derivatives leads to low accuracy and instability results in many cases. In this paper, we propose a new method using a combination of Taylor series expansion and upward continuation for computing vertical derivatives. This method has been tested on the gravitational anomaly of infinite horizontal cylinder in both cases with and without random noise for higher accurate and stable than Hilbert transform method and Laplace equation method, especially in the case of noise input data. This vertical derivative method is applied successfully to calculate the downward continuation according to Taylor series expansion method. The downward continuation is also tested on both complex synthetic models and real data in the East Vietnam Sea (South China Sea). The results reveal that by calculating this new vertical derivative, the downward continuation method gave higher accurate and stable than the previous downward continuation methods.


2009 ◽  
Vol 52 (2) ◽  
pp. 511-518 ◽  
Author(s):  
Hui ZHANG ◽  
Long-Wei CHEN ◽  
Zhi-Xin REN ◽  
Mei-Ping WU ◽  
Shi-Tu LUO ◽  
...  

2021 ◽  
Vol 36 (6) ◽  
pp. 622-631
Author(s):  
Shanshan Guan ◽  
Bingxuan Du ◽  
Dongsheng Li ◽  
Yuan Wang ◽  
Yu Zhu ◽  
...  

The Ground-source Airborne Time-domain Electromagnetic (GATEM) system has advantages for high efficiency and complex areas such as mountainous zone. Because of ignoring the impact of flight height, the section interpretation method seriously affects the interpretation and imaging accuracy of shallow anomalies. The PID controller iteration downward continuation method is proposed. Based on the original iteration continuation method, the differential coefficient and integral coefficient are added. The result shows that the new method remarkably decreases the iteration number, and the accuracy are verified by comparison with the numerical integration solution. The PID controller iteration downward continuation method is applied to the interpretation of GATEM data. For synthetic data, the interpretation results of continued electromagnetic response are closer to the true model than the z = 30 m interpretation results. The method is also applied to GATEM field data in Yangquan City, Shanxi Province, China. The interpretation results perform reliability using PID controller iteration downward continuation method in a GATEM field.


2021 ◽  
Vol 1885 (4) ◽  
pp. 042003
Author(s):  
Ze Wang ◽  
Qi Zhang ◽  
Mengchun Pan ◽  
Dixiang Chen ◽  
Zhongyan Liu ◽  
...  

2020 ◽  
Vol 72 (1) ◽  
Author(s):  
Yuan Yuan ◽  
Xiangyu Zhang ◽  
Wenna Zhou ◽  
Guochao Wu ◽  
Weidong Luo

Abstract Obtaining horizontal edges and the buried depths of geological bodies, using potential field tensor data directly is an outstanding question. The largest eigenvalue of the structure tensor is one of the commonly used edge detectors for delineating the horizontal edges without depth information of the potential field tensor data. In this study, we presented a normalized largest eigenvalue of structure tensor method based on the normalized downward continuation (NDC) to invert the source location parameters without any priori information. To improve the stability and accuracy of the NDC calculation, the Chebyshev–Pade´ approximation downward continuation method was introduced to obtain the potential field data on different depth levels. The new approach was tested on various models data with and without noise, which validated that it can simultaneously obtain the horizontal edges and the buried depths of the geological bodies. The satisfactory results demonstrated that the normalized largest eigenvalue of structure tensor can describe the locations of geological sources and decrease the noise interference magnified by the downward continuation. Finally, the method was applied to the gravity data over the Humble salt dome in USA, and the near-bottom magnetic data over the Southwest Indian Ridge. The results show a good correspondence to the results of previous work.


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