Background-oriented schlieren (BOS) imaging, owing to its non-contact nature and high spatiotemporal resolution, has become an important measurement technique in field experiments of explosion mechanics. However, due to strong illumination interference, scattering from detonation products, and the inherently weak and morphologically complex shockwave signature, automatic and accurate extraction of the shock front from BOS images remains highly challenging. To address this issue, we propose a structure-aware weighted variational optical flow method (SAW-VF) for robust quantification of the high-speed transient displacement field of shockwaves. The proposed approach minimizes a purpose-designed energy functional. Specifically, the data fidelity term combines a first-order photometric constraint with a second-order Hessian-invariance constraint, substantially enhancing sensitivity to the local line-like geometric features of shock fronts. In addition, a spatially adaptive weighting mechanism driven by normalized cross-correlation (NCC) is introduced to dynamically suppress the adverse influence of severely distorted regions on the estimation. Moreover, an anisotropic regularization term inspired by Perona-Malik diffusion is employed to effectively preserve the sharp motion boundaries of the shock front. To cope with large displacements, the optimization is embedded in a coarse-to-fine Gaussian pyramid framework. Building upon the estimated displacement field, we further develop a physics model–driven shock-front fitting method, in which the shock front is accurately extracted via maximum-inlier-set optimization coupled with shockwave dynamical constraints. Finally, the shock radius and propagation velocity are estimated using geometric calibration and temporal information, and the overpressure is quantitatively determined in a non-contact manner based on the Rankine-Hugoniot theory. In TNT explosion experiments, the proposed method achieves a relative error of 0.93%−9.85% with respect to pressure sensor measurements, demonstrating its effectiveness and accuracy for non-intrusive overpressure measurement of shockwaves.

After the explosion, in order to rescue the ocean engineering in a timely manner, the explosion point position needs to be accurately located. In order to improve the accuracy of positioning the spatial coordinates of the explosion point, after studying the characteristics of the shock waves, a method for positioning the spatial coordinates of the explosion point is proposed. The current method corrects the average velocity of the shock waves, and the effectiveness of the method is also tested by examples. The principle of this method is: through the overpressure empirical formula to obtain the burst distance R corresponding to each measured point, the distance from the coordinates of one point in space to each measurement point is r, the shock wave average velocity correction factor is K, which could be adjusted to improve the accuracy of the positioned result; and when the total relative errors of each measured point are the smallest, which is the coordinate of the positioned explosion point. The example results show that the accuracy of the coordinates of the explosion point is high. And based on the characteristics of the shock wave, a spherical charge data processing method is proposed, which can effectively improve the accuracy of position. By using it, the coordinate error of the explosion point is reduced from 0.66 m to 0.08 m, the relative error of the explosion point is reduced from 6.68% to 0.86%, and the maximum relative error of K is reduced from 4.95% to 0.31%. The coordinate error of the cylindrical charge example was 0.31 m, the relative error of the explosion point is 14.75%, and the maximum relative error of K was 11.55%. The error of the original data has a great influence on the position accuracy, and in order to ensure the high accuracy of the position result, the data with excessive error should be excluded.