Optical altimetry for microscale sediment layers

Measuring microscale sediment layers is critically important for geophysical, biomedical, and engineering systems. Here, we propose a novel optical method to quantify spatial distributions of microparticle layers at grain-size resolution. The method does not require specialized equipment, but utilizes a standard digital camera and scattered light from the sediment layers. With a simple implementation, it can account for inherent spatial trends originating from non-ideal lighting conditions, ensuring high flexibility and extensibility. Micrometric resolution is achieved in both spatial and depth dimensions, and demonstrated for underwater ripple patterns formed by fine organic particles. Our promising results offer direct practical application of the method to study granular layers, biofilms, and dust layer formation.