Celebrating the Retirement of Dr. Susan Ustin and a Lifetime of Unparalleled Accomplishments


Celebrating the Retirement of Dr. Susan Ustin and a Lifetime of Unparalleled Accomplishments



Dr. Susan Ustin, Distinguished Professor and Director of the UC Davis Center for Spatial Technology and Remote Sensing (CSTARS), has been pioneering research in remote sensing for over four decades. She is an Elected Fellow of the American Geophysical Union (AGU), an Elected Senior Member of the Institute of Electrical and Electronic Engineers, and recipient of an honorary doctorate from the University of Zurich. She has also served as mentor and advisor to countless Ph.D. and masters students throughout her impressive career.

The John Muir institute of the Environmental is proud to call Dr. Ustin our Associate Director of Research. We cannot thank her enough for her contributions to the success of our institute or to the field of remote sensing as a whole. It is with a sense of gratitude that we share some, but certainly not all, of her accomplishments below.

Ustin began her academic journey when she obtained her Ph.D. in Botany in 1983, when the concept of anthropogenically-caused climate change was being recognized. For her Ph.D. dissertation, she conducted high carbon dioxide (CO2) experiments on plants at 400 parts per million (ppm). At that time, it seemed as if it would take nearly 80 years reach 400 ppm. However, humanity passed the 400 ppm threshold in 2016.

The early 1980’s marked a time when the concept of “Earth as a system” came into focus. The 1982 Goody Report to NASA (Richard Goody, Chair) was groundbreaking in that it envisioned a truly interdisciplinary climate research program that considered the Earth’s coupled physical, chemical and biological processes and their interconnections between land, atmosphere and oceans. This report led to plans for a new generation of Earth Observing Satellites. In preparation for this effort, Ustin was contacted by Barrett (Barry) N. Rock, from the NASA Jet Propulsion Lab (JPL) to offer her a post-doctoral position that would capitalize on her expertise in plant physiology and ecology. At this time, the field of remote sensing was mainly populated by men, primarily engineers and geologists.

Ustin learned from Rock that JPL was going to build the first imaging spectrometer that year, with $50,000 funding from the JPL Director’s Discretionary Funds. Ustin was intrigued by the possibilities for using this technology to scale-up leaf-level physiology measurements to the regional level; however, she still knew little about remote sensing. Nonetheless, as she had no other job offers at the time, she accepted JPL’s offer.

Ustin began her post-doc with JPL working from UC Davis in October 1983 with a field trip to Owens Valley, where the first flights of the Airborne Imaging Spectrometer (AIS) were flown. Ustin was eight months pregnant and had just returned from a 6-week trip to Libya with her husband but that didn’t stop her from participating in reconnaissance for the project. Ustin considers this project to be especially important for her career as she met and worked with many of the most innovative and knowledgeable people in remote sensing at that time, including several from NASA Headquarters (HQ).

Ustin subsequently worked with Dr. John Adams, a professor of planetary sciences was also an investigator on the Owens Valley project. Over the next several years, she worked closely with several individuals who were also making great strides in the field including Milton Smith, Alan Gillespie, Dar Roberts, and others. These collaborations led to a seminal paper on spectral mixture models in 1990 as well an introduction to JoBea Cimino (later Jobea Way) by Jack Paris, both from the JPL Radar group.

Way received a grant in 1986 called the “Simultaneity Study” from Shelby Tilford, then Director of the Earth Science program at NASA HQ, to research whether there was a requirement for radar and optical instruments to simultaneously observe plant physiological processes. This grant was a precursor to the “Mission to Planet Earth”, which later evolved into the Earth Observing System (EOS). Ustin took advantage of UCD’s Dave Goldhamer’s evapotranspiration experiment on walnut trees at the UC Kearney Experiment Station and produced several papers, including one by Vern Vanderbilt et al. that the Institute of Electrical and Electronics Engineers (IEEE) awarded as “Best Paper of the Year.” Vern Vanderbilt turned out to be a career-long collaborator, who helped Ustin understand the complex physical interactions of light with plant canopies.

In 1986, a second ground-breaking report was released from the NASA Earth System Sciences Advisory Council entitled “Earth System Science Overview. A Program for Global Change,” or the so-called “Bretherton Report,” chaired by Francis P. Bretherton. It emphasized the need for a systematic approach to understanding climate change. The report boldly called for a scientific understanding of the entire earth system at the global scale and a capacity for predicting environmental changes based on a suite of measurements for atmosphere, land and ocean.

These two reports, as well as two subsequent reports published in 1988 (Sally Ride, “Leadership and America’s Future in Space” and Bretherton, “Earth System Science: A Closer View”) led the NASA Earth Science program to develop an unprecedented era of advances in remote sensing through the Earth Observing System (EOS).

On July 25, 1989 NASA held the first EOS Investigator’s Working Group Meeting in an auditorium with more than 1,000 investigators, mostly all men and only a handful of women in attendance. Ustin had been selected as a member of the HIRIS Science Team, and was a liaison to the SAR team, but both instruments were later cut from the program in a descoping due to budget cuts in 1994.

In 1991, Ustin was hired as an Assistant Professor of Environmental Resource Science in the Hydrology program of the UC Davis Department of Land, Air, and Water Resources. Because her remote sensing research required more computing power than most other faculty needed at the time, she was asked to hire an IT person to maintain her computers. This led to hiring Quinn Hart, to manage Ustin’s sole IBM computer. Quinn Hart transitioned this role to Bob Haxo, who ultimately trained George Scheer, the current IT manager for the John Muir Institute of the Environment. Soon after, researcher analyst Mui Lay joined her lab. Ustin attributes much of her success to the contributions of these staff members.

From 1991 to 1996 EOS experienced several budget cuts which severely impacted Ustin’s lab and research. Still, she continued to study spectroscopy measurements in collaboration with many colleagues, including Stéphane Jacquemoud, Kyaw Tha Paw U, and Jack Paris. Paw U with Ustin and Paris were ultimately selected as SIR-C (Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar) science team members as part of the EOS program. This instrument was flown on the Space Shuttle Endeavour in April 1994 on and again in October 1994 for 11 days each, ultimately producing data used to create the SRTM (Shuttle Radar Topographic Mapper) the first digital topographic map for most of the Earth’s land surface.

Ustin, in 1991, was then asked to join Piers Sellers’ NASA Biosphere-Atmosphere Interactions Interdisciplinary Science program as part of the “west coast team” led by Hal Mooney and Chris Field. When Sellers later left science to become an astronaut (he made three trips to the International Space Station assembling components of the station), the team included many notable colleagues including Dave Randall, C.J. (Jim) Tucker, Ruth DeFries, Joe Berry, Pam Matson, Peter Vitousek, Inez Fung and Jim Colatz among others. This team was funded for a decade until October 2000. In 2018 the entire team had a reunion in Fort Collins to celebrate the program and Piers Sellers’ life.

It was during these later years in her career that Ustin’s accomplishments truly became clear. In 2010, Ustin was awarded an Honorary Doctorate for her work advancing imaging spectrometry from the University of Zurich. In 2017, she was elected a Fellow of the American Geophysical Union, for her pioneering work.

Ustin knows the near-future looks bright for her work. The 2017 Decadal Survey provided its top recommendation for a hyperspectral satellite in low earth orbit. A German (DLR) instrument, EnMAP, is nearly ready for launch, and an Italian imaging spectrometer (Prisma) was launched in 2019. In addition the German DLR’s DESIS (DLR Earth Sensing Imaging Spectrometer) and the Japanese METI’s (Ministry of Economy, Trade, and Industry) HISUI (Hyperspectral Imager Suite) imaging spectrometers will be hosted on the International Space Station (ISS) by the end of 2019. These imaging spectrometers will be joined in two future NASA-approved missions: Earth Surface Mineral Dust Source Investigation (EMIT), scheduled for the ISS in 2021, and Surface Biology and Geology (SBG), a free-flying satellite scheduled for 2025 launch.

Ustin has been dissertation advisor, mentor and teacher to countless students throughout her career. She has been Ph.D. dissertation advisor for 24 students and served on the Ph.D. dissertation committee for 29 students. She has mentored 27 post-doctoral scholars, many of whom were foreign scientists. Ustin states that these people have enriched her life beyond description.

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