An Asymmetric Beamforming Method Based on Arithmetic Phase Difference Weighting in CSAMT

Traditional controlled-source audio-frequency magnetotellurics (CSAMT) radiates symmetric beams using a grounded dipole (GSD). Only tiny fraction of radiant energy is taken advantage during the far-field (Ff) observation due to low directivity GSD. In order enhance signal-to-noise ratio (SNR) Ff observation, it necessary reduce transceiving distance (TD) or increase transmitting power (TP), but both methods will cause many problems. Further, when tensor method for GSDs in two vertical directions be employed radiate energy, and then series problems occur such as an asymmetry SNR if geological conditions under vary widely. An arithmetic phase difference (APd) weighting asymmetric beamforming (ABFM) CSAMT proposed this paper, which uses GSD array instead single GSD, signal with APd transmitted control wavefront beam steering. A significant enhancement (about 3 dB) by collecting region concern (RoC) ABFM. The analysis simulation results demonstrate that premise same TD TP, ABFM has obvious advantages improving utilization CSAMT. other words, APd-weighted can deal complex noise environment field better than traditional method.