Development Of A Spatio-Temporal Acoustic Pressure Measurement Technique Utilizing Background Oriented Schlieren Technique
Sayaka Ichihara (1), Masato Yamagishi (2), Ayumu Ishibashi (1), Yuta Kurashina (1), Masanori Ota (2), Yoshiyuki Tagawa (1)
1. Tokyo University of Agriculture and Technology, Tokyo, Japan
2. Chiba University, Chiba, Japan
DOI:
We developed an image and optical-based technique to measure spatio-temporal acoustic pressure fields using BOS instead of a hydrophone. Fast checker demodulation (FCD) and vector tomography (VT) were employed for displacement detection and axisymmetric tomography, respectively. In experiments, BOS and hydrophones of different diameters measured focused ultrasound, revealing BOS's higher spatial resolution and ability to capture temporal evolution at 4.554 MHz. However, BOS showed systematic errors under amplified pressure. Using synthetic data, we identified that FCD's underestimation issues could be defined by the integrated power spectra of distorted images. Thus, BOS with FCD and VT provides high-resolution measurements but requires criteria to avoid displacement underestimation.