…Wherein we’ll learn about the LISST-Tau and some of the ongoing developments at Sequoia.

(Part XIII can be found here https://www.sequoiasci.com/article/the-history-of-sequoia-part-xiii/ )

In the fall of 2019 Sequoia got the opportunity to develop a dedicated transmissometer. While the laser-diffraction based LISSTs have always measured transmission, Sequoia never had a dedicated transmissometer for the customers interested in just measuring transmission. Five prototypes were developed in five months and flown on gliders in 2020 for testing with excellent results

LISST-Tau profiles from 4.5 day glider deployment.

The LISST-Tau was officially announced in the spring of 2021. Current applications include ‘standard’ oceanographic use in moored, profiled and vehicle mounted applications as well as eelgrass monitoring. One of our latest videos feature the LISST-Tau.

Sequoia’s VP Science & Technology Dr. Wayne Slade was funded in early 2020 to develop a deep-sea mining sensor – LISST-RTSSV. Its purpose is to monitor suspended sediment size and settling velocity of deep-sea mining plumes in real time. The funding came on an SBIR from DoE’s ARPA-E program and is an on-going collaboration with SBIR partners Dr. Thomas Peacock (MIT) and Dr. Matthew Alford (Scripps), finishing 12/31/2022. A prototype LISST-RTSSV was deployed in a deep-sea mining trial in the spring of 2021 . A second trial is planned for fall 2022, with production units being available probably in a year, around Q4, 2023.

In 2021, Dr. Slade was funded via a Phase I and later a Phase II SBIR from NASA to develop a hyper-spectral absorption meter – a companion instrument to Sequoia’s successful Hyper-bb hyper-spectral backscatter instrument. This work is a collaboration between Sequoia and Dr. Mike Twardowski of Sunstone Scientific in FL. The Phase II project ends in late 2023, with commercial units expected to be available around Q2, 2024.

Finally, Dr. Slade, together with Meg Estapa from University of Maine was granted an STTR Phase I from NSF at Christmas 2021. The STTR is for the development of a sensor to measure carbon fluxes associated with sinking particles in the ocean. This work is still very much in the development stage, but it is the hope that a commercial instrument for floats can be available in late 2025 or early 2026.

In conclusion: There’s lot going on at Sequoia and after more than 27 years in business, Sequoia is still going strong and has an exciting and growing array of products for the aquatic scientist