Correcting EM system bandwidth limitations

Macnae, J 2015, 'Correcting EM system bandwidth limitations', in ASEG-PESA Volume 2015 Number 1 2015 24th International Geophysical Conference and Exhibition - Geophysics and Geology together for Discovery, Perth, WA, Australia, 15-18 February 2015, pp. 1-4.


Document type: Conference Paper
Collection: Conference Papers

Title Correcting EM system bandwidth limitations
Author(s) Macnae, J
Year 2015
Conference name Australian Society of Exploration Geophysicists 24th International Geophysical Conference and Exhibition
Conference location Perth, WA, Australia
Conference dates 15-18 February 2015
Proceedings title ASEG-PESA Volume 2015 Number 1 2015 24th International Geophysical Conference and Exhibition - Geophysics and Geology together for Discovery
Publisher CSIRO
Place of publication Clayton South, Vic, Australia
Start page 1
End page 4
Total pages 4
Abstract All EM transmitters, sensors and data acquisition systems have bandwidth limitations. Transmitters have upper bandwidth limitations due to finite slew rate issues, and systems have a lower bandwidth set by the base frequency used. Receivers and data acquisition systems ideally should have a flat bandwidth response that spans the transmitted signal bandwidth. The data acquisition system should sample fast enough to capture the highest frequencies of interest, with anti-alias filters to prevent data contamination from unwanted signals. Sensors however may have physical bandwidth limitations, for example fluxgates and feedback MT sensors may have an upper corner frequency of a few kHz, and ARMIT and feedback MT sensors have lower corner frequencies in the sub 1 Hz range. In many cases, the sensor corner frequency can be mathematically described as a single- or multi-pole response. In this case, it is possible to exactly deconvolve the data to exactly correct for the sensor imperfection. A limitation of this process is that noise as well as signal may be amplified in this correction process. Without correction, data may be incorrectly modelled or interpreted. This paper illustrates the correction of fluxgate (mostly a time delay of hundred or more microseconds), ARMIT 2 (where a significant but exact correction is required), ANT23 feedback and 3D3 dBdt data.
Subjects Electrical and Electromagnetic Methods in Geophysics
Keyword(s) Electromagnetics
bandwidth
fluxgate
ARMIT
coil
feedback.
Copyright notice © 2015 CSIRO © ASEG 2015
Versions
Version Filter Type
Access Statistics: 19 Abstract Views  -  Detailed Statistics
Created: Mon, 02 Oct 2017, 12:15:00 EST by Catalyst Administrator
© 2014 RMIT Research Repository • Powered by Fez SoftwareContact us