Much of the US coastal zone is covered in a veneer of mobile sediment, and the size of this sediment determines under what conditions IT moves

Accurate measurement of coastal sediment grain size is critical for work on coastal erosion, shoreline change, total water level forecasting, storm impact predictions, planning, designing nature-based coastal protections, and other coastal resilience projects. Measurement of grain size is time consuming, costly, and requires a laboratory. Inaccurate measurements result in degraded performance of models, plans, predictions, and forecasts. To address slow measurement speed and high cost-per-sample, we have built a new handheld camera-based system that uses on-device machine learning, does not require calibration, and provides accurate field measurements of grain size within 1 second, ~1,000,000X faster than lab quotes of 2 weeks. We propose three research objectives to dramatically improve the performance of our technology for coastal sites of the US, regardless of sediment size, distribution, color, and composition: first, field collections to grow our training dataset; second, machine learning model development to increase performance and reduce training data requirements; third, targeted work to determine presence and percentage of specific minerals used for some coastal projects. We anticipate the proposed work will lead to the development of a device that: 1) can accurately measure all types of sediment present along the continental US coastline; 2) contains a new pretrained machine learning model - made using weak supervision - that will improve model results; and 3) detects the presence and weight percentage of specific minerals used in some coastal projects. Quantitative metrics will allow US to measure the success of each research objective. The implication of the proposed work is the development of a new instrument able to measure sediment grain size quickly and accurately in the field at any US coastal location. Customer discovery work from 150+ interviews suggests: 1) a field device for grain size measurement is an innovation that will compress project timelines, reduce costs (labor, subcontracting, lab services), and enable rapid inhouse field monitoring; 2) this device will be transformative for industries tasked with measuring and monitoring, such as coastal engineering firms, coastal restoration outfits, geotechnical firms, and local, state, federal agencies. Our innovation will compress project timelines, reduce costs (labor, subcontracting), and enable rapid in-house field analysis for coastal restoration and engineering firms and local, state, and federal agencies.