Compensation for aircraft effects of magnetic gradient tensor measurements in a towed bird
Chunxiao Xiu 1 2 4 Xiaohong Meng 1 2 4 Lianghui Guo 1 2 Sheng Zhang 3 Xingdong Zhang 1 21 Key Laboratory of Geo-detection (China University of Geosciences, Beijing), Ministry of Education, Beijing 100083, China.
2 School of Geophysics and Information Technology, China University of Geosciences, Beijing 100083, China.
3 Development and Research Center (National Geological Archives of China), Beijing 100037, China.
4 Corresponding authors. Email: xiuchunxiao@163.com; mxh@cugb.edu.cn
Exploration Geophysics 49(5) 713-725 https://doi.org/10.1071/EG16028
Submitted: 10 March 2016 Accepted: 2 August 2017 Published: 1 September 2017
Abstract
The effect of magnetic interference from the helicopter on full gradient tensor measurements acquired in a towed bird is substantial and must be corrected if airborne data are to be usable. During the actual flight process, the helicopter’s and bird’s attitudes, as well as the relative position between the helicopter and bird, change continuously. Thus the traditional method of compensation for aircraft effects is not suitable for this mode of measurement. For a particularly long towline, magnetic interference from helicopter can be reduced, but the errors introduced by substantial variations in altitude and orientation of the bird may be even greater than the magnetic interference from the helicopter. We have developed a compensation model from the perspective of forward modelling to correct full gradient tensor data measured in a towed bird for the magnetic effects of the helicopter, taking into account variations in attitude of the bird and helicopter. We designed training flight projects that allow compensation parameters to be estimated. The feasibility of the compensation method was verified by modelling and simulated flight tests. Finally, this method was applied to real data and the data quality was improved.
Keyword: aeromagnetic compensation.
References
Bickel, S. H., 1979, Small signal compensation of magnetic fields resulting from aircraft maneuvers: IEEE Transactions on Aerospace and Electronic Systems, 15, 515–525Clark, D. A., Schmidt, P. W., Coward, D. A., and Huddleston, M. P., 1998, Remote determination of magnetic properties and improved drill targeting of magnetic anomaly sources by Differential Vector Magnetometry (DVM): Exploration Geophysics, 29, 312–319
| Remote determination of magnetic properties and improved drill targeting of magnetic anomaly sources by Differential Vector Magnetometry (DVM):Crossref | GoogleScholarGoogle Scholar |
Deng, P., Tan, B., and Lin, C. S., 2011, Pretreatment of compensation for aircraft’s magnetic interference: Journal of Naval University of Engineering, 23, 58–61
Gopal, B. V., Sarma, V. N., and Rambabu, H. V., 2004, Real time compensation for aircraft induced noise during high resolution airborne magnetic surveys: Journal of Indian Geophysical Union, 8, 185–189
Holstein, H., and Anastasiades, C., 2010, A numerically stable magnetic anomaly formula for uniform polyhedra: SEG Technical Program, Expanded Abstracts, 1188–1192.
Leliak, P., 1961, Identification and evaluation of magnetic field sources of magnetic airborne detector MAD equipped aircraft: IRE Transactions on Aerospace and Navigational Electronics, ANE-8, 95–105
| Identification and evaluation of magnetic field sources of magnetic airborne detector MAD equipped aircraft:Crossref | GoogleScholarGoogle Scholar |
Leslie, K., Blay, K., Clark, D., Schmidt, P., Tilbrook, D., and Foley, C. P., 2007, Helicopter trial of magnetic tensor gradiometer: 19th International Geophysical Conference & Exhibition (ASEG 2007), Extended Abstract, 1–4.
Liu, X. J., 2009, Study on aeromagnetic compensation technique: M.Sc. thesis, Jilin University [in Chinese].
Liu, Y., Rong, L. L., Jiang, K., Chang, K., Kong, X. Y., and Xie, X. M., 2014, Simulation and experimental on shielding effect of radio frequency for superconducting magnetometer: Diwen Wuli Xuebao, 36, 136–139
Lv, J. W., Yu, Z. T., Huang, J. L., and Zhou, J., 2013, The compensation method of vehicle magnetic interference for the magnetic gradiometer: Advances in Mathematical Physics, 2013, 1–5
| The compensation method of vehicle magnetic interference for the magnetic gradiometer:Crossref | GoogleScholarGoogle Scholar |
Schmidt, P., Clark, D., Leslie, K., Bick, M., Tilbrook, D, and Foley, C, 2004, GETMAG – a SQUID magnetic tensor gradiometer for mineral and oil exploration: Exploration Geophysics, 35, 297–305
| GETMAG – a SQUID magnetic tensor gradiometer for mineral and oil exploration:Crossref | GoogleScholarGoogle Scholar |
Stolz, R., Zakosarenko, V., Schulz, M., Chwala, A., Fritzsch, L., Meyer, H. G., and Kostlin, E. O., 2006, Magnetic full-tensor SQUID gradiometer system for geophysical applications: The Leading Edge, 25, 178–180
| Magnetic full-tensor SQUID gradiometer system for geophysical applications:Crossref | GoogleScholarGoogle Scholar |
Tolles, W. E., and Lawson, J. D. 1950, Magnetic compensation of MAD equipped aircraft: Airborne Instruments Laboratory Inc., Mineola, N.Y., Report 201–1.
Wang, Y., Qiu, L. Q., Shi, W., Jiang, K., Rong, L. L., and Kong, X. Y., 2015, Study on compensation of unbalance of full-tensor LTS-SQUID magnetic gradiometer: Diwen Wuli Xuebao, 37, 169–173
Williams, P. M., 1993, Aeromagnetic compensation using neural networks: Neural Computing & Applications, 1, 207–214
| Aeromagnetic compensation using neural networks:Crossref | GoogleScholarGoogle Scholar |
Wu, J., Qiu, L. Q., Kong, X. Y., Rong, L. L., and Xie, X. M., 2015a, A new low temperature SQUID magnetometer based on GPS synchronization: Chuangan Jishu Xuebao, 28, 1347–1353
Wu, J., Rong, L. L., and Xie, X. M., 2015b, New high-precision superconducting magnetometer based on SQUID bootstrap circuit: Instrument Technique and Sensor, 9, 28–34
Young, J. A., Keenan, S. T., Clark, D. A., Leslie, K. E., Sullivan, P., Fairman, P., Williams, C., Foley, C. P., and Billings, S. D., 2010, A superconducting magnetic tensor gradiometer for underwater UXO detection: 21st International Geophysical Conference & Exhibition (ASEG-PESA 2010), 1–4.
Zhang, N., Sun, B. Q., and Lin, C. S., 2012, Research on inductive magnetic field of motion platform magnets modeling: Ship Electronic Engineering, 32, 61–62
| 1:CAS:528:DC%2BC3sXhsVeqtbvJ&md5=8715390ada3fa994198dc02c48211fc5CAS |
Zhang, Y., Zhao, Y. X., and Chang, S., 2014, An aeromagnetic compensation algorithm for aircraft based on fuzzy adaptive Kalman filter: Journal of Applied Mathematics, 2014, 405671
Zhou, J. J., Lin, C. S., and Yang, Z. Y., 2012, Calculation of ellipsoid eddy-current moment under varying magnetic field: College Physics, 31, 43–46
Zhou, J. J., Lin, C. S., and Xie, J., 2014, A method for separate inductive magnetic moment and residual magnetic moment of ferromagnet: Journal of Wuhan University of Technology (Transportation Science & Engineering), 38, 580–584