MEASURING COASTAL SEDIMENT GRAIN SIZE INSTANTLY USING INSTAGRAIN, A HAND-HELD CAMERA WITH ON-DEVICE MACHINE LEARNING

Grain size is a first order control on sediment transport rates and thus morphological change in coastal environments. In many coastal settings grain size can be highly variable over short space and time scales. Quantifying this variability is time consuming (e.g., sieve analysis, settling tube) or costly (e.g., laboratory instruments, labor). Furthermore all of these measurement techniques are typically performed in the lab, not in the field. Here we discuss the development of Instagrain, a new camera that enables instant grain size measurements (~2 sec.) in the field by bundling image acquisition and grain size analysis using on-device machine learning (Goldstein et al., 2022). We report results from coastal field sites in the USA.