### Abstract

The Hilbert transform defined via the Hartley transform in contrast with the well-known Fourier transform is mathematically illustrated with a couple of geophysical applications. Although, the 1-D Fourier and Hartley transforms are identical in amplitude with a phase difference of 45°, the Hilbert transform effectively differs when defined as a function of the Hartley transform in certain geophysical applications. It may be noted here that the Hilbert transform defined through Fourier and Hartley transforms while possessing the same magnitude differs in phase by 270°. It is derived and shown mathematically that the evaluation of depth of subsurface targets is directly equal to the abscissa of the point of intersection of the gravity (magnetic) field and the Hartley-Hilbert transform; however, it is not the case with the Fourier-Hilbert transform. The practical applications are illustrated with the interpretation of gravity anomaly due to an inclined sheet-like structure across the Mobrun ore body, Noranda, Quebec, Canada, and the vertical magnetic anomaly due to a cylindrical structure over a narrow band of quartzite magnetite, Karimnagar, India. The entire process can be automated.

Original language | English |
---|---|

Pages (from-to) | 1622-1626 |

Number of pages | 5 |

Journal | Computers and Geosciences |

Volume | 37 |

Issue number | 10 |

DOIs | |

Publication status | Published - Oct 2011 |

### Fingerprint

### Keywords

- Amplitude
- Analytical signal
- Fourier transform
- Frequency
- Hartley transform
- Origin
- Phase

### ASJC Scopus subject areas

- Information Systems
- Computers in Earth Sciences

### Cite this

*Computers and Geosciences*,

*37*(10), 1622-1626. https://doi.org/10.1016/j.cageo.2011.02.003

**An alternate and effective approach to Hilbert transform in geophysical applications.** / Sundararajan, N.; Al-Lazki, Ali.

Research output: Contribution to journal › Article

*Computers and Geosciences*, vol. 37, no. 10, pp. 1622-1626. https://doi.org/10.1016/j.cageo.2011.02.003

}

TY - JOUR

T1 - An alternate and effective approach to Hilbert transform in geophysical applications

AU - Sundararajan, N.

AU - Al-Lazki, Ali

PY - 2011/10

Y1 - 2011/10

N2 - The Hilbert transform defined via the Hartley transform in contrast with the well-known Fourier transform is mathematically illustrated with a couple of geophysical applications. Although, the 1-D Fourier and Hartley transforms are identical in amplitude with a phase difference of 45°, the Hilbert transform effectively differs when defined as a function of the Hartley transform in certain geophysical applications. It may be noted here that the Hilbert transform defined through Fourier and Hartley transforms while possessing the same magnitude differs in phase by 270°. It is derived and shown mathematically that the evaluation of depth of subsurface targets is directly equal to the abscissa of the point of intersection of the gravity (magnetic) field and the Hartley-Hilbert transform; however, it is not the case with the Fourier-Hilbert transform. The practical applications are illustrated with the interpretation of gravity anomaly due to an inclined sheet-like structure across the Mobrun ore body, Noranda, Quebec, Canada, and the vertical magnetic anomaly due to a cylindrical structure over a narrow band of quartzite magnetite, Karimnagar, India. The entire process can be automated.

AB - The Hilbert transform defined via the Hartley transform in contrast with the well-known Fourier transform is mathematically illustrated with a couple of geophysical applications. Although, the 1-D Fourier and Hartley transforms are identical in amplitude with a phase difference of 45°, the Hilbert transform effectively differs when defined as a function of the Hartley transform in certain geophysical applications. It may be noted here that the Hilbert transform defined through Fourier and Hartley transforms while possessing the same magnitude differs in phase by 270°. It is derived and shown mathematically that the evaluation of depth of subsurface targets is directly equal to the abscissa of the point of intersection of the gravity (magnetic) field and the Hartley-Hilbert transform; however, it is not the case with the Fourier-Hilbert transform. The practical applications are illustrated with the interpretation of gravity anomaly due to an inclined sheet-like structure across the Mobrun ore body, Noranda, Quebec, Canada, and the vertical magnetic anomaly due to a cylindrical structure over a narrow band of quartzite magnetite, Karimnagar, India. The entire process can be automated.

KW - Amplitude

KW - Analytical signal

KW - Fourier transform

KW - Frequency

KW - Hartley transform

KW - Origin

KW - Phase

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U2 - 10.1016/j.cageo.2011.02.003

DO - 10.1016/j.cageo.2011.02.003

M3 - Article

VL - 37

SP - 1622

EP - 1626

JO - Computers and Geosciences

JF - Computers and Geosciences

SN - 0098-3004

IS - 10

ER -