Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
A Multi–Frequency Electromagnetic Image System
A digital, multi–frequency electromagnetic image system is developed based on the induction principle for subsurface imaging near a sewage pipe. This system, which features a broadband operation, can transmit sinusoidal in a frequency range of 1.25 KHz to 10 KHz. A microprocessor is used for all controls and computations for both the transmitter and receiver circuits. Synchronous sampling is used for digitization in order to compute the phase as well as the amplitude of the receiving signal. The system operates in the frequency domain and both the phase and amplitude information can be computed through a digital signal–processing algorithm. Test results indicate that the multi–frequency EM sensor is superior in both the missing manhole detection and general subsurface conductivity imaging to the conventional single–frequency sensors. For loop antennas with a spacing of 0.5 m, the system has a phase resolution of about 1° and an amplitude resolution of about 0.5%
A Multi–Frequency Electromagnetic Image System
A digital, multi–frequency electromagnetic image system is developed based on the induction principle for subsurface imaging near a sewage pipe. This system, which features a broadband operation, can transmit sinusoidal in a frequency range of 1.25 KHz to 10 KHz. A microprocessor is used for all controls and computations for both the transmitter and receiver circuits. Synchronous sampling is used for digitization in order to compute the phase as well as the amplitude of the receiving signal. The system operates in the frequency domain and both the phase and amplitude information can be computed through a digital signal–processing algorithm. Test results indicate that the multi–frequency EM sensor is superior in both the missing manhole detection and general subsurface conductivity imaging to the conventional single–frequency sensors. For loop antennas with a spacing of 0.5 m, the system has a phase resolution of about 1° and an amplitude resolution of about 0.5%
A Multi–Frequency Electromagnetic Image System
Zhang, Qing (Autor:in) / Chen, Xuemin (Autor:in) / Jiang, Xiuhan (Autor:in) / Liu, Ce (Autor:in)
Computer‐Aided Civil and Infrastructure Engineering ; 18 ; 113-120
01.03.2003
8 pages
Aufsatz (Zeitschrift)
Elektronische Ressource
Englisch
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