The Effect of Hardware-Computed Travel Time on Localization Accuracy in the Inversion of Experimental (Acoustic) Waveform Data

Abstract

Abstract-This study aims to advance hardware-level computations for travel-time tomography applications in which the wavelength is close to the diameter of the information that has to be recovered. Such can be the case, for example, in the imaging applications of (1) biomedical physics, (2) astro-geophysics and (3) civil engineering. Our aim is to shed light on the effect of that preprocessing the digital waveform signal has on the inversion results and to find computational solutions that guarantee robust inversion when there are incomplete and/or noisy measurements. We describe a hardware-level implementation for integrated and thresholded travel-time computation (ITT and TTT). We compare the ITT and TTT approaches in inversion analysis with experimental acoustic travel-time data recorded using a ring geometry for the transmission and measurement points. The results obtained suggest that ITT is essential for maintaining the robustness of the inversion with imperfect signal digitization and sparsity. In order to ensure the relevance of the results, the specifications of the test setup were related to those of applications (1)-(3).

DISCUS – The Deep Interior Scanning CubeSat mission to a rubble pile near-Earth asteroid

“…The first one of these (i) will enable an enhanced backscattering measurement; our numerical results (Takala et al, 2017a) suggest that with the choice γ = 25 • the accuracy and reliability of the bistatic tomography outcome is superior compared to the monostatic (single-spacecraft) case. The second option (ii) will allow a higher signal-to-noise ratio due to one-way signal paths and tomographic traveltime measurements, performed, e.g., in CONSERT (Takala et al, 2017b;Kofman et al, 2015).…”