Optical flow tracking velocimetry of near-field explosions

Abstract

To better understand the complex dynamics and physics associated with the rapid expansion of the detonation product fireball following an explosion, it is imperative to have a full description of its associated velocity field. Typical experimental techniques rely on simple single-point measurements captured from pressure transducers or Hopkinson pressure bars. In this technical design note, we aim to improve the current state-of-the-art by introducing a means to determine full velocity fields from high-speed video using Optical Flow Tracking Velocimetry. We demonstrate the significance of this method from our results by comparing velocity fields derived from high-speed video and a validated numerical model of the same case. A wider use of this technique will allow researchers to elucidate spatial and temporal features of explosive detonations, which could not be obtained thus far using single- point measurements.

A Review of Blast Loading in the Urban Environment

“…Two common methods include image subtraction and image correlation, both of which have been widely used or discussed in other sources, e.g., [121][122][123]. Alternatively, optical flow tracking velocimetry methods [124] may be used.…”

Experimental verification of different analytical approaches for estimating underwater explosives

“…Advanced measurement devices enforced with software post-processing enable registering high-speed phenomena, for instance, the temperature on a bullet in flight (Kerampran et al, 2020) or velocity and motion of a fireball due to explosion (Higham et al, 2021). Moreover, elaborate numerical methods aid understanding complex phenomena (Kciński and Szturomski, 2020), such as failure behaviour of structural elements (Baranowski et al, 2021) or probabilistic analysis of human safety after explosion in crowded area (Gan et al, 2022).…”

Satellite video target tracking based on kernel correlation filtering and trajectory prediction

“…Scholars have carried out research in the field of target tracking for many years, and have proposed many reliable tracking algorithms. At present, video target tracking methods can be roughly divided into traditional methods such as Mean shift [4], optical flow method [5], and Kalman filtering [6], as well as correlation filtering methods [7] and deep learning methods [8]. Among them, the correlation filtering method has become a popular tracking algorithm in recent years due to its high performance and high speed [9] [10], which is very suitable for satellite video small target tracking.…”