scholarly journals Comparison of head-related impulse response measurement approaches

2013 ◽  
Vol 134 (2) ◽  
pp. EL223-EL229 ◽  
Author(s):  
Martin Rothbucher ◽  
Kajetan Veprek ◽  
Philipp Paukner ◽  
Tim Habigt ◽  
Klaus Diepold
Keyword(s):  
Impulse Response ◽  
Response Measurement

The quantitative advantages of using B-field sensors in time-domain EM measurement for mineral exploration and unexploded ordnance search

Geophysics ◽  
2012 ◽  
Vol 77 (4) ◽  
pp. WB137-WB148 ◽  
Author(s):  
Michael W. Asten ◽  
Andrew C. Duncan
Keyword(s):  
Impulse Response ◽  
Time Constant ◽  
Exponential Decay ◽  
Time Domain ◽  
Step Response ◽  
Late Time ◽  
Additional Parameter ◽  
Unexploded Ordnance ◽  
Response Measurement ◽  
Response Systems

The use of simple models for decay of conductive targets under conductive overburden and for the decay of magnetically permeable conductive steel objects allows quantitative consideration of the advantages of the use of magnetic-field detectors in time-domain electromagnetic (TEM) measurements, or more generally, the advantage of step response over impulse response TEM systems. We identified eight advantages of the step response versus impulse-response systems. The first two advantages relate to the inductive limit (early time) decay behavior, in which a target response amplitude is largely dependent on geometrical rather than conductivity parameters. Five further advantages occur when measuring response of a target in a conductive host or under conductive overburden; the maximum target-to-overburden response occurs 25%–30% earlier in time, the earliest target detection time occurs a factor 2–4 earlier, and the amplitude advantage of target-to-overburden response is a factor in the range of 1–10 for the step versus impulse-response systems, respectively. These advantages agree quantitatively with field observations on a chalcopyrite orebody under conductive cover. We used a model response for a conductive permeable sphere to derive mathematically consistent approximations for the power-law and exponential decay behaviors for step and impulse responses of metal objects, from which the onset of late-time exponential decay of EM responses of unexploded ordnance occurs about a factor of two earlier in time for the step response. This earlier-time transition together with the higher signal-to-noise ratio available from the step-response measurement makes measurement of the fundamental time-constant of unexploded ordnance (UXO) possible for medium and large UXO where the time constant is in the range of tens of milliseconds. This time-constant thus becomes accessible as an additional parameter for UXO characterization and discrimination.

scholarly journals Wide-band modelling of tower-footing grounding systems based on the impulse response measurement

2019 ◽  
Vol 29 (29) ◽  
pp. 1-11
Author(s):  
Ranko Jasika ◽  
Jovan Mrvić ◽  
Stefan Obradović ◽  
Ninoslav Simić
Keyword(s):  
Impulse Response ◽  
Wide Band ◽  
Response Measurement

A time‐domain EM system measuring the step response of the ground

Geophysics ◽  
1984 ◽  
Vol 49 (7) ◽  
pp. 1010-1026 ◽  
Author(s):  
G. F. West ◽  
J. C. Macnae ◽  
Y. Lamontagne
Keyword(s):  
Magnetic Fields ◽  
Impulse Response ◽  
Electric Fields ◽  
Time Domain ◽  
Wide Band ◽  
Step Response ◽  
System Function ◽  
Response Measurement ◽  
Resistivity Method ◽  
Electric And Magnetic Fields

A wide‐band time‐domain EM system, known as UTEM, which uses a large fixed transmitter and a moving receiver has been developed and used extensively in a variety of geologic environments. The essential characteristics that distinguish it from other systems are that its system function closely approximates a stepfunction response measurement and that it can measure both electric and magnetic fields. Measurement of step rather than impulse response simplifies interpretation of data amplitudes, and improves the detection of good conductors in the presence of poorer ones. Measurement of electric fields provides information about lateral conductivity contrasts somewhat similar to that obtained by the gradient array resistivity method.

Impulse Response Measurement of Few-Mode Fiber Systems by Coherence-Recovered Linear Optical Sampling

2017 ◽  
Vol 35 (20) ◽  
pp. 4392-4398 ◽  
Author(s):  
Naoto Kono ◽  
Fumihiko Ito ◽  
Daisuke Iida ◽  
Tetsuya Manabe
Keyword(s):  
Impulse Response ◽  
Response Measurement ◽  
Optical Sampling ◽  
Linear Optical
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