Resultant force on grains of a real sand dune: How to measure it?

TL;DR

This paper introduces a novel imaging and computational approach combining experiments, simulations, and neural networks to accurately measure forces on individual grains in sand dunes, advancing granular dynamics research.

Contribution

It presents a new method integrating high-speed imaging, simulations, and deep learning to estimate forces on dune grains, enabling detailed analysis of granular interactions in natural environments.

Findings

High accuracy force estimation on dune grains

Applicable to various objects in satellite imagery

Enhances understanding of granular-fluid interactions

Abstract

Dunes are bedforms found on sandy terrains shaped by fluid flow on Earth, Mars, and other celestial bodies. Despite their prevalence, understanding dune dynamics at the grain scale is challenging due to the vast number of grains involved. In this study, we demonstrate a novel approach to estimate the forces acting on individual dune grains using images. By combining subaqueous experiments, high-speed camera recordings, discrete numerical simulations, and a specially trained convolutional neural network, we can quantify these forces with high accuracy. This method represents a breakthrough in studying granular dynamics, offering a new way to measure forces not only on dune grains but also on smaller objects, such as rocks, boulders, rovers, and man-made structures, observed in satellite images of both Earth and Mars. This technique expands our ability to analyze and understand fluid-grain interactions in diverse environments.