SEQUOIA SCIENTIFIC - Key Persons
All of my life I have been fascinated by what makes things work. My whole career as a mechanical engineer has just been an extension of the curiosity I had as a kid. I think I have the best job in the world…I get paid to invent, build, and make work a wide variety of interesting things.
I started my career as a fluid dynamics laboratory technician at Flow Research while going to school at the University of Washington. I learned many things about experimental science and fluid mechanics. In addition to learning the science I also learned the art of machining. My hours spent working with and talking to the "elders" of the machine shop taught me how to be a much better mechanical engineer.
In 1988 I met Dr. Yogi Agrawal. After graduating I started working with Yogi full time and I have been working with him ever since. We have built many unique instruments for our oceanographic research. Most, if not all, included some kind of optics and electronics. Some examples are Laser Doppler Velocimeters, Laser particle size analyzers, and underwater cameras. All of which were in-situ instruments that required close coupling of electronics, optics and mechanical components.
Yogi and I started Sequoia in early 1995 on the idea that we could build a better science and technology company. We wanted to work at a place that could do both high caliber contract science and manufacture state of the art research equipment. We feel that we have achieved that goal.
Job Titles:
- Emeritus Vice President and Senior Scientist
Job Titles:
- Sequoia VP Engineering & Production, Retires
- VP, Engineering & Production
On July 1st, 2023 Sequoia's VP Engineering & Production Mr. David Dana retired. David started his engineering journey at the age of six when he discovered … Continue reading David Dana, Sequoia VP Engineering & Production, retires
My initial life plan was to become a theoretical physicist, Stephen Hawking was an early idol. But in high school I had a phenomenal geography teacher, so that's what I ended up studying in college instead. My Ph.D. thesis (2001) dealt with suspended particle dynamics in Danish coastal waters, and had lots of LISST results in it. One of Sequoia's very first customers was my supervisor, Professor Morten Pejrup at University of Copenhagen, and to a large extent my life and career has been intertwined with Sequoia since he bought LISST-100 s/n 1019 from Sequoia in 1997. (That unit, btw, is still going strong today (2019), and despite decades of use it has only been back for service once in 22 years).
A series of early visits to Sequoia during my Ph.D. (1998-2001) and subsequent postdocs in Canada and the UK (2002-2007) led me to being hired by Sequoia and relocating to Seattle in November 2007. During my Ph.D. I used a LISST to study the dynamics sedimentology of suspended particles in Danish coastal waters, leading to some of the first papers on in-situ estimates of flocculation time scales, the influence of flocculation on remote sensing estimates of particle concentration, and a new settling velocity model. During my 2001 visit to Sequoia I started working on the randomly shape particle studies, which culminated in 2008 with the JGR publication of the randomly shaped particle matrices. Sequoia is still the only company in the world to have done this. During my post doc in Canada I developed the INSSECT sampling platform for studying dynamic sedimentology in coastal areas, deployed in a number of locations in Canada and the Adriatic Sea 2002-2005. My work on Schlieren, which can potentially affect all optical instruments, also was initiated during my Canadian postdoc, and finalized during my postdoc in the UK (2005-2007). Upon relocating to Seattle work continued on the randomly shaped particle topic, leading to a couple of papers in Applied Optics with published phase functions for randomly shaped particles.
I left Sequoia in 2013 but was brought back as President 1/1/2019 as Yogi retired.
Job Titles:
- News
- VP, Science & Technology
My research focuses on characterization of oceanic particles and their dynamics using optical methods, especially using multi-spectral, multi-angle, and polarized measurements of inherent optical properties. As a research scientist at Sequoia Scientific, one of my primary aims is the development of instrumentation and methods for measuring particle optical properties and the deployment of these technologies in observing systems, ship-based flowthrough systems, and on autonomous and other challenging platforms. I received a Ph.D. in Oceanography in 2011 focused on ocean particle optics. I am experienced in deploying optical sensors in coastal and open ocean environments, in design and execution of laboratory studies using these same sensors, in the analysis of data from field and laboratory experiments, and in computer modeling of the optical properties of particles. I have additional research experience in signal and image processing and intelligent algorithm design.
Current Research Interests
Yogi Agrawal arrived at University of California, Berkeley in 1969, after a B. Tech. degree with Distinction (like Cum Laude) from the Indian Institute of Technology in Mumbai, India. After a Master's degree in 1970 that included an award-winning simulation of tumors of the heart that produce murmurs, he completed his Ph.D. in 1975. His thesis involved developing a laser Doppler velocimetry instrument that he used to study the development of flow in the human aorta - an issue then tied to formation of plaques. He did a brief post-doctoral stint at the Lawrence Berkeley Laboratory, studying dynamics of lean combustion - an issue suddenly brought to prominence with the rise of environmentalism. In 1978, he sought new challenges in the field of Oceanography, joining Woods Hole Oceanographic Institution. His interests in high quality measurements lead to the first deep-ocean laser Doppler velocimeter (LDV), autonomous, operating in deep ocean depth of 5,000m. He followed this with measurements of turbulent energy dissipation rates using a near-surface version of the LDV, hung from a tower in Lake Ontario. This work demonstrated enhanced dissipation in the surface when wave-breaking occurs. The work has been widely cited. In 1988, seeking greener pastures, he migrated to the Seattle area and met and retained Chuck Pottsmith as his assistant - a partnership that would endure for 30 years. After brief stints at two companies, he founded Sequoia Scientific, Inc. together with Chuck Pottsmith (as VP). Recognizing the need for particle size distribution (PSD) and settling velocity distribution (SVD) as fundamental inputs to sediment transport models -neither of which could be measured at that time in situ, he proceeded to develop appropriate laser diffraction technology instruments. The first such instrument, LISST-100 was developed with US Navy funding and demonstrated its capacity to produce the desired PSD measurements. Several papers followed, with observations in storms and coasts. This capability remains unmatched to date (May 2021). This instrument was the first product of Sequoia Scientific, Inc..