Tetrahedral omnidirectional full-tensor gravitational wave detector

Abstract

We propose a new tetrahedral configuration of three-axis inertial sensors, whose signals when combined create an isotropic sensitivity to gravitational waves. This arrangement provides total sky coverage and full-tensor measurements of the gravity gradient using only four test masses (TMs), compared to the six TMs of the previously studied TIGA and superconducting omnidirectional gravitational radiation observatory designs. Since weakly suspending a TM in all three directions is difficult due to the gravity bias, we also present the directional sensitivity plot for the case where only horizontal displacements are measured. This antenna pattern is no longer isotropic, and results in a maximum sensitivity to minimum sensitivity ratio of 2:1 in power. The full gravity gradient tensor can in this case still be reconstructed if the platform is sufficiently isolated from ground tilt.