Mendenhall Research Fellowship Program

S53. Monitoring inland water features using fused ground and satellite radar observations


Closing Date: April 30, 2021

This Research Opportunity will be filled depending on the availability of funds. All application materials must be submitted through USAJobs by 11:59 pm, US Eastern Standard Time, on the closing date.


Background:  Existing and upcoming satellite radars are revolutionizing measurement of Earth’s inland waters from the unique vantage point of space.  In order to pursue its mission to monitor, analyze, and predict dynamics of the Earth System, the U.S. Geological Survey (USGS) is seeking applications for a full-time researcher position with focus on hydrologic radar remote sensing through its Mendenhall Research Fellowship Program. 

The selected Fellow is expected to leverage upcoming satellite radars to improve hydrologic observing systems and advance our understanding of the terrestrial water cycle and water resource quantity and availability.  The Fellow will be based in the Hydrologic Remote Sensing Branch of the USGS Water Mission Area (WMA) and will collaborate with the Terrestrial Hydrology Group at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, CA and the USGS Earth Resources Observation and Science (EROS) Center in Sioux Falls, SD.  The Fellow will have the opportunity to spend time at JPL (pending NASA approval) and at EROS and will work with a multi-disciplinary team having expertise in both hydrology and satellite remote sensing.  This position will enable access to the tremendous scientific resources of both USGS and NASA and provide the Fellow with an opportunity to pursue their own scientific interests while furthering the Earth science goals of both agencies.   

The USGS WMA operates the largest hydrologic monitoring network in the US and has expertise in inland water monitoring, mapping, and modeling.  WMA has the goal of operationally producing terrestrial hydrology observations with seamless national coverage, high resolution, and high accuracy.  These geospatial hydrologic observations need to be delivered in near-real-time to meet WMA mission requirements that include flood and drought planning and forecasting; assessing and forecasting water availability for human and ecological use; and improving models used for water resources prediction and decision support. The USGS Core Science System Mission Area (CSS) is the civilian mapping agency for the Nation and has broad expertise in Earth-observation remote-sensing science.  CSS maintains the National Hydrography Dataset (NHD), administers the Landsat mission and related science programs, and operationally produces satellite-based hydrologic data layers for a wide array of uses. 

NASA runs the national civilian space program and plans to launch the Surface Water and Ocean Topography (SWOT) and NASA-ISRO Synthetic Aperture Radar (NISAR) satellite missions in 2022.  These radar missions are managed by JPL for NASA and are expected to provide transformative new observations of inland water features.  Coupling SWOT and NISAR data with recent advancements in data science and increased high-performance computing resources presents an exciting opportunity to expand global hydrologic observing capabilities from remote sensing.   

Description of the Research Opportunity: The Mendenhall Fellow will work with an interdisciplinary USGS/NASA team to advance technology and methods for estimating water quantity from satellite radar data.  The target satellite sensors to be used are those of SWOT (i.e. a radar interferometer and a radar altimeter), NISAR (i.e. L and S-band synthetic aperture radars), and Sentinel-1 (i.e. C-band synthetic aperture radar). The target ground-based data, for integration with satellite data, are from existing USGS national monitoring networks that measure streams, lakes, reservoirs, snow, and soil moisture. A new WMA research program, the Next Generation Water Observing System Program, is testing new observation technologies in targeted river basins of the US, which will provide opportunities to couple remote sensing with new in-situ sensing technologies.  

The Fellow will have access to broad USGS and NASA hydrologic and remote sensing expertise, as well as recently developed high-performance computing resources, collocated massive collections of remote sensing data; containerized workflows and other analytical tools; national-scale operational hydrologic models of runoff and water availability; and national hydrologic monitoring networks. 

The Fellow will work on novel techniques to produce integrated hydrologic datasets that combine ground-based observations and remote-sensing observations to reduce bias, capture spatial variability, and improve surface-water and water cycle characterization. One of the key advantages that remote-sensing observations brings to a seamless hydrologic monitoring network is the ability to observe dynamic hydrologic and hydraulic processes on watershed, water body, and river reach scales, thus taking advantage of spatial averaging of local scale complexity. 

Hydrologic variables of interest include river stage and discharge, reservoir/lake level and storage, soil moisture, and snowpack.  Potential research and development topics include: 

  • Techniques for merging multi-scale data and reducing errors in hydrologic observations.   

  • Translation of satellite mission performance and error budgets into error estimates for related hydraulic and hydrologic state variables. 

  • Evaluation of river discharge on a reach scale that incorporates geomorphic and river channel morphologic features into the estimation of hydraulic processes   

  • Development of process-based algorithms to monitor storage change, inflow and outflow of river basins 

  • Design of prototype operational hydrologic monitoring systems that demonstrate stability and robustness 

Applicants are encouraged to propose research aligning with one of the above topics and with their own expertise and experience. Applicants are also encouraged to contact research advisors listed below to discuss research directions early in the application process. 

The Fellow will be organizationally stationed within the USGS Hydrologic Remote Sensing Branch of the Observing Systems Division of the USGS.  Pending NASA approval, up to three months per year may be spent at JPL in Pasadena, CA working in collaboration with scientists in the Terrestrial Hydrology Group and collocated with NISAR and SWOT mission operations.  The opportunity to work onsite with scientists at the USGS EROS Center in Sioux Falls, SD, is also available.   

The Fellow will collaborate with scientists from the USGS WMA and CSS and from NASA JPL and will be mentored by experts in hydrology, data science, remote sensing, and high-performance computing. The Fellow will join a USGS project team and support the work of the project with their research. Potential USGS projects to join include the Remote Sensing of Discharge, National Hydro-Geospatial Fabric, and Integrated Water Prediction Community Testbed.  

A successful applicant must show evidence of the following: 

  • Demonstrated record of peer-reviewed publications related to science and applications for hydrology and remote sensing 

  • Demonstrated research record using radar data for hydrologic science 

  • Excellent oral (including public speaking) and written communication skills. 

  • Experience building and/or working in collaborative, diverse and inclusive team environments 

  • Strong interpersonal and communication skills 

The following knowledge and skills are preferred: 

  • Advanced knowledge of satellite hydrologic remote sensing methodologies and applications including but not limited to observational techniques (in situ and remote), and their combination in the form of scientific analyses, data assimilation, machine learning, and cloud- and/or high-performance-computing 

  • Strong interest in the justification, formulation, and implementation of new satellite hydrologic monitoring systems. 

Proposed Duty Station: Leetown, WV; Reston, VA; or other USGS office in the U.S.

Pending NASA approval, up to three months per year may be spent at the Jet Propulsion Laboratory (JPL) in Pasadena, CA working in collaboration with scientists in the Terrestrial Hydrology Group and collocated with NISAR and SWOT mission operations. The opportunity to work onsite with scientists at the USGS Earth Resources Observation and Science (EROS) Center in Sioux Falls, SD, is also available.

Areas of PhD: Computer science, data science, mathematics, physics, engineering, remote sensing, geographic/cartographic sciences, hydrologic sciences, hydraulics (candidates holding a Ph.D. in other relevant disciplines may be considered). 

Qualifications: Applicants must meet one of the following qualifications:  Research GeographerResearch HydrologistResearch Physical Scientist, or Research Engineer.    

(This type of research is performed by those who have backgrounds for the occupations stated above. However, other titles may be applicable depending on the applicant's background, education, and research proposal. The final classification of the position will be made by the Human Resources Specialist.) 

Human Resources Office Contact:  Audrey Tsujita, 916-278-9395,



Jack Eggleston

Chief, Hydrologic Remote Sensing Branch
USGS Water Resources Mission Area
Phone: 703-459-3903

Christopher J Crawford, Ph.D.

Research Physical Scientist
Earth Resources and Observation Science (EROS) Center
Phone: 605-594-2859

John W Jones

Research Geographer
USGS Water Resources Mission Area
Phone: 703-994-3224

David Bjerklie

Phone: 860-291-6770

Cédric David

Group Supervisor
NASA-Jet Propulsion Laboratory
Phone: 818-354-4416

Renato Frasson

Research Scientist
NASA-Jet Propulsion Laboratory

Sang-Ho Yun

NASA-Jet Propulsion Laboratory