Career Timeline

I joined JPL as a research scientist in the Earth and Space Sciences Division after a year as a National Research Council Postdoctoral Associate. My initial work focused on the theoretical basis of passive microwave remote sensing, developing radiative transfer models for emission from the Earth's ocean and land surfaces.

This foundational period, following my graduate studies at MIT, established the mathematical and physical frameworks that would underpin my research for the following four decades.

During this period, I made contributions to the theory of microwave emission from the land surface. I developed algorithms for retrieving soil moisture and vegetation water content from satellite brightness temperature observations, publishing in scientific journals including the IEEE Transactions on Geoscience and Remote Sensing and the Journal of Geophysical Research, among others.

My work on the Scanning Multichannel Microwave Radiometer (SMMR) aboard the Seasat and Nimbus-7 satellites provided early demonstrations of satellite-based sea surface temperature and land surface soil moisture estimation.

I served for four years at NASA Headquarters in Washington, D.C., as a Program Scientist within the Earth Science Division. In this role I contributed to agency-level planning for Earth observation missions, including the development of the Earth Observing System (EOS) Data and Information System (EOSDIS) program.

This period broadened my perspective from individual research to the strategic direction of the national Earth science program, and deepened my engagement with the mission formulation process.

Returning to JPL, I expanded my research into instrument design and mission architecture for future Earth observation systems. I contributed to studies of L-band microwave radiometer systems and their potential for global soil moisture mapping.

I also contributed to the science team for the TRMM (Tropical Rainfall Measuring Mission) and participated in the formulation of the Aqua mission's AMSR-E instrument science.

I served as a science team member for the Advanced Microwave Scanning Radiometer for EOS (AMSR-E) aboard NASA's Aqua satellite, launched in 2002. I led the development of the AMSR-E soil moisture retrieval algorithm, which became one of the first operational global soil moisture products from space.

This work directly informed the design requirements for the dedicated soil moisture mission that would become SMAP.

I was appointed Project Scientist for the Soil Moisture Active Passive (SMAP) mission, leading the science definition from Phase A formulation through instrument development, algorithm design, and pre-launch validation planning. I chaired the SMAP Science Definition Team and coordinated the international science community's engagement with the mission.

I retired as Project Scientist in 2013 but continued to work with the project as a team member. SMAP launched on January 31, 2015, and began science operations in April 2015.

Following SMAP's successful launch and commissioning, I participated in the early science operations phase, including the release of the first global soil moisture data products and the initiation of the validation program.

I retired from NASA JPL in 2016 after 39 years of service, leaving a body of work that spans remote sensing theory, instrument design, mission leadership, and a lasting contribution to the global understanding of Earth's water cycle.