• MetaBlue introduces a low-cost passive acoustic metasurface that turns any ultrasonic transmitter into a directional super-transmitter. • The metasurface embeds direction-dependent spectral patterns, enabling accurate angle-of-arrival estimation with a single hydrophone. • A novel EM-acoustic mixed time-of-arrival method uses the transducer’s low-frequency EM leakage as a timing reference, eliminating shared clocks. • The combined AoA and ToA approach delivers full 3D localization using only one low-cost anchor. • Experiments in pools, tanks, and outdoor water show average AoA error of 8.7°, 3D localization error 0.37 m beyond 10 m. • Even with a single anchor, the system maintains 0.73 m precision, reducing hardware costs and deployment complexity.
Article Summaries:
- MetaBlue is a low‑cost, passive acoustic metasurface that turns a standard ultrasonic transmitter into a directional “super‑transmitter.” By embedding direction‑dependent spectral patterns into the emitted waveform, the system can estimate the angle of arrival (AoA) with a single hydrophone. For distance measurement, MetaBlue uses a novel EM‑acoustic mixed time‑of‑arrival (ToA) technique that exploits the transducer’s low‑frequency electromagnetic leakage as a timing reference, eliminating the need for shared clocks. Field tests in pools, tanks and outdoor environments show an average AoA error of 8.7°, 3‑D localization error of 0.37 m at >10 m, and 0.73 m precision using only one anchor. The approach offers a simpler, cheaper alternative to large arrays or multiple synchronized anchors for underwater positioning.
Sources: