A discussion of bias in magnetotelluric responses
Magnetic-field noise biases magnitudes of magnetotelluric response functions such as resistivity, impedance, and the induction vector (tipper). This is particularly severe in the so-called dead band between about 1- and 10-s periods. The standard approach to remove these biases is to use a magnetic...
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2009
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| Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00168033_v74_n4_pF59_Pomposiello http://hdl.handle.net/20.500.12110/paper_00168033_v74_n4_pF59_Pomposiello |
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paper:paper_00168033_v74_n4_pF59_Pomposiello2023-06-08T14:39:00Z A discussion of bias in magnetotelluric responses Electric fields Magnetic fields Magnetism Magnetotellurics Electric and magnetic fields Induction vectors Inversion algorithm Magnetic field noise Parallel component Remote sites Response functions Unbiased estimates Electric variables measurement algorithm correlation data inversion electromagnetic field estimation method magnetotelluric method measurement method Magnetic-field noise biases magnitudes of magnetotelluric response functions such as resistivity, impedance, and the induction vector (tipper). This is particularly severe in the so-called dead band between about 1- and 10-s periods. The standard approach to remove these biases is to use a magnetic remote reference. In cases where this is unavailable or does not work because noise is correlated at the local and remote sites, it is possible to extract unbiased estimates using an inversion algorithm that predicts the magnitude from the phase. However, an important condition for this to be successful is that phase estimates are unbiased. Phase can be biased if parallel components of the electric and magnetic fields are correlated. This arises when the structure is 3D or when a 2D response is estimated in coordinates not parallel to strike. Improvements in electric field measurements make electric field references a viable option for estimating low-bias responses up to periods approaching 1000 s. © 2009 Society of Exploration Geophysicists. All rights reserved. 2009 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00168033_v74_n4_pF59_Pomposiello http://hdl.handle.net/20.500.12110/paper_00168033_v74_n4_pF59_Pomposiello |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
Electric fields Magnetic fields Magnetism Magnetotellurics Electric and magnetic fields Induction vectors Inversion algorithm Magnetic field noise Parallel component Remote sites Response functions Unbiased estimates Electric variables measurement algorithm correlation data inversion electromagnetic field estimation method magnetotelluric method measurement method |
| spellingShingle |
Electric fields Magnetic fields Magnetism Magnetotellurics Electric and magnetic fields Induction vectors Inversion algorithm Magnetic field noise Parallel component Remote sites Response functions Unbiased estimates Electric variables measurement algorithm correlation data inversion electromagnetic field estimation method magnetotelluric method measurement method A discussion of bias in magnetotelluric responses |
| topic_facet |
Electric fields Magnetic fields Magnetism Magnetotellurics Electric and magnetic fields Induction vectors Inversion algorithm Magnetic field noise Parallel component Remote sites Response functions Unbiased estimates Electric variables measurement algorithm correlation data inversion electromagnetic field estimation method magnetotelluric method measurement method |
| description |
Magnetic-field noise biases magnitudes of magnetotelluric response functions such as resistivity, impedance, and the induction vector (tipper). This is particularly severe in the so-called dead band between about 1- and 10-s periods. The standard approach to remove these biases is to use a magnetic remote reference. In cases where this is unavailable or does not work because noise is correlated at the local and remote sites, it is possible to extract unbiased estimates using an inversion algorithm that predicts the magnitude from the phase. However, an important condition for this to be successful is that phase estimates are unbiased. Phase can be biased if parallel components of the electric and magnetic fields are correlated. This arises when the structure is 3D or when a 2D response is estimated in coordinates not parallel to strike. Improvements in electric field measurements make electric field references a viable option for estimating low-bias responses up to periods approaching 1000 s. © 2009 Society of Exploration Geophysicists. All rights reserved. |
| title |
A discussion of bias in magnetotelluric responses |
| title_short |
A discussion of bias in magnetotelluric responses |
| title_full |
A discussion of bias in magnetotelluric responses |
| title_fullStr |
A discussion of bias in magnetotelluric responses |
| title_full_unstemmed |
A discussion of bias in magnetotelluric responses |
| title_sort |
discussion of bias in magnetotelluric responses |
| publishDate |
2009 |
| url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00168033_v74_n4_pF59_Pomposiello http://hdl.handle.net/20.500.12110/paper_00168033_v74_n4_pF59_Pomposiello |
| _version_ |
1768543734956294144 |