A selection of our members:
1. S. Ebihara, "Directional borehole radar with dipole antenna array using optical modulators," IEEE Trans. Geosci. Remote Sens., vol. 42, no. 1, pp. 45-58, January 2004.
Paper #1 proposes introducing the optical modulator system in order to realize a dipole array antenna for directional borehole radar. Also it shows that the proposed radar can estimate three-dimensional location of subsurface objects with field experimental results.
2. S. Ebihara and T. Yamamoto, "Resonance Analysis of Circular Dipole Array Antenna in Cylindrically Layered Media," IEEE Trans. Geosci. Remote Sens., vol. 44, no. 1, pp. 22-31, January 2006.
Paper #2 deal with phase-sequence resonance in a dipole array antenna. This resonance is a kind of mutual coupling among the dipole antennas in a borehole, and we analyzed the resonance with the modified Method of Moments.
3. S. Ebihara and Y. Hashimoto, "MoM Analysis of Dipole Antennas in Crosshole Borehole Radar, and Field Experiments," IEEE Trans. Geosci. Remote Sens., vol. 45, no. 8, pp. 2435 – 2450, Aug. 2007.
Paper #3 deals with the borehole effects, which is influence of a borehole on the antenna, in crosshole borehole radar. It shows water inside the borehole influences the radar signals seriously, comparing the Method of Moments data and the field experiment data.
4. S. Ebihara, A. Sasakura and T. Takemoto, "HE11 Mode Effect on Direct Wave in Singlehole Borehole Radar," IEEE Trans. Geosci. Remote Sens., vol. 49, no. 2, pp. 854-867, Feb. 2011.
Paper #4 shows that eccentricity of the radar sonde in singlehole borehole radar influences direct wave significantly. According to the paper, the guided wave, HE11 mode, is excited, only when the radar sonde is eccentered in a water-filled borehole.
5. S. Ebihara, H. Hanaoka, T. Okumura and Y. Wada, "Interference Criterion for Coaxial-Fed Circular Dipole Array Antenna in a Borehole" , IEEE Trans. Geosci. Remote Sens. (in press).
Paper #5 proposes the new directive antenna for the directional borehole radar. This provides the method to design the proper conducting cylinder, which includes feed lines, electronic circuits and batteries.