A quadrupolar array for measuring the complex permittivity of the ground: application to Earth prospection and planetary exploration

Quadrupolar arrays have been used for mapping ground resistivity; low-frequency currents are injected into the Earth and the induced potential drop is simultaneously measured with electrodes necessarily in contact with the Earth's surface. A new version of the quadrupolar array is proposed; this instrument makes use of high-frequency signals, does not require any mechanical contact with the ground and measures the resistivity and permittivity of the subjacent medium. A practical design applicable to unmanned planetary missions is presented.