Abstract：
To improve the inversion accuracy of time-domain airborne electromagnetic data, we propose a parallel 3D inversion algorithm for airborne EM data based on the direct Gauss–Newton optimization. Forward modeling is performed in the frequency domain based on the scattered secondary electrical field. Then, the inverse Fourier transform and convolution of the transmitting waveform are used to calculate the EM responses and the sensitivity matrix in the time domain for arbitrary transmitting waves. To optimize the computational time and memory requirements, we use the EM “footprint” concept to reduce the model size and obtain the sparse sensitivity matrix. To improve the 3D inversion, we use the OpenMP library and parallel computing. We test the proposed 3D parallel inversion code using two synthetic datasets and a field dataset. The time-domain airborne EM inversion results suggest that the proposed algorithm is effective, efficient, and practical.
. 3D parallel inversion of time-domain airborne EM data[J]. APPLIED GEOPHYSICS, 2016, 13(4): 701-711.
[1]
Brodie, R., and Sambridge, M., 2006, A holistic approach to inversion of frequency-domain airborne EM data: Geophysics, 71, G301−G312.
[2]
Carrigy, M. A., and Kramers, J. W., 1973, Guide to the Athabasca oil sands area: Prepared for the Canadian Society of Petroleum Geologists Oil Sands Symposium, information series 65.
[3]
Chen, J., and Raiche, A., 1998, Inverting AEM data using a damped eigenparameter method: Exploration Geophysics, 29, 128−132.
[4]
Christensen, N. B., Fitzpatrick, A., and Munday, T., 2010, Fast approximate inversion of frequency- domain electromagnetic data: Near Surface Geophysics, 8, 1−15.
[5]
Cox, L. H., and Zhdanov, M. S., 2008, Advanced computational methods for rapid and rigorous 3D inversion of airborne electromagnetic data: Communications in Computational Physics, 3, 160−179.
[6]
Cox, L. H., Wilson, G. A., and Zhdanov, M. S., 2010, 3D inversion of airborne electromagnetic data using a 移动脚印: Exploration Geophysics, 41, 250−259.
[7]
Cox, L. H., Wilson, G. A., Zhdanov, M. S., 2012, 3D inversion of airborne electromagnetic data: Geophysics, 77(4), WB59−WB69.
[8]
Egbert, G. D., 1994, A new stochastic process on the sphere: application to characterization of long-period global scale external sources: 14th Workshop on Electromagnetic Induction in the Earth and Moon, Brest, France.
[9]
Egbert, G. D., and Kelbert, A., 2012, Computational recipes for electromagnetic inverse problems: Geophys. J. Int., 189(1), 251−267.
[10]
Ellis, R. G., 1995, Joint 3D EM inversion: International Symposium on Three-Dimensional Electromagnetics, Expanded Abstracts.
[11]
Ellis, R. G., 1998, Inversion of airborne electromagnetic data: Exploration Geophysics, 29, 121−127.
[12]
Haber, E., 2014, Computational methods in geophysical electromagnetics: SIAM, Philadelphia.
[13]
Li, Y. X., Qiang, J. K. and Tang, J. T., 2010, A research on 1-D forward and inverse airborne transient electromagnetic method: Chinese Journal Geophysics, 53(3), 751−759.
[14]
Macnae, J., King, A., Stolz, N. et al., 1998, Fast AEM data processing and inversion: Exploration Geophysics, 29, 163−169.
[15]
Mao, L. F., Wang, X. B. and Li, W. J., 2011, Research on 1D inversion method of fix-wing airborne transient electromagnetic record with flight altitude inversion simultaneously: Chinese Journal Geophysics, 54(8), 2136−2147.
[16]
Newman, G. A., and Alumbaugh, D. L., 1995, Frequency-domain modeling of airborne electromagn- etic responses using staggered finite differences: Geophysical Prospecting, 43(8), 1021−1042.
[17]
Oldenburg, D. W., Haber, E., and Shekhtman, R., 2013, Three dimensional inversion of multisource time domain electromagnetic data: Geophysics, 78(1), E47−E57.
[18]
Raiche, A., Annetts, D., and Sugeng, F., 2001, EM target response in complex hosts: ASEG 15th Geophysical Conference and Exhibition, Brisbane,
[19]
Siripunvaraporn, W., and Egbert, G. D., 2000, An efficient data-subspace inversion method for 2-D magnetotelluric data: Geophysics, 65(3), 791−803.
[20]
Tartaras, E., and Beamish, D., 2005, Laterally constrained inversion of fixed-wing frequency- domain AEM data: 12th European Meeting of Environmental and Near Surface Geophysics, Helsinki.
[21]
Viezzoli, A., Auken, E., and Munday, T., 2009, Spatially constrained inversion for quasi 3D modeling of airborne electromagnetic data - an application for environmental assessment in the Lower Murray Region of South Australia: Exploration Geophysics, 40, 173−183.
[22]
Vallée, M. A., Smith, R. S., 2009, Inversion of airborne time-domain electromagnetic data to a 1D structure using lateral constraints: Near Surface Geophysics, 7, 63−71.
[23]
Wilson, G. A., Raiche, A. P., and Sugeng, F., 2006, 2.5D inversion of airborne electromagnetic data: Exploration Geophysics, 37(4), 363−371.
[24]
Wolfgram, P., and Karlik, G., 1995, Conductivity- depth transform of GEOTEM data: Exploration Geophysics, 26, 179−185.
[25]
Yang, D. K., Oldenburg, D. W., and Haber, E., 2014, 3-D inversion of airborne electromagnetic data parallelized and accelerated by local mesh and adaptive soundings: Geophys. J. Int., 196, 1492− 1507.
[26]
Zhang, Z. Y., Tan, H. D., Wang, K. P., Lin, C. H., Zhang, B. and Xie, M. B., 2016, Two-dimensional inversion of spectral induced polarization data using MPI parallel algorithm in data space: Applied Geophysics, 13(1), 13−24.
2016, Vol. 13 
