Jasmeet Judge specializes in microwave remote sensing. Her training in electrical engineering and in atmospheric, oceanic, and space sciences is complemented by skills in physics and computer science. The main goal of her research is to understand how water interacts with soil and vegetation by using both remote sensing and computer models, such as hydrologic and crop growth models. These models capture the current understanding of these interactions in mathematical formulations and predict the flow of water in the soil and crops through time. With remote sensing, larger areas of the landscape can be monitored, providing linkages among smaller, local scales to larger, regional and global scales.
Combining remote sensing observations and the models is Judge’s approach to understanding water in the top meter of the soil, called the root zone. The moisture in the root zone is vital to plant life and has an impact on weather and heat exchange between the land and the atmosphere. Her work takes a unique look at this layer of the earth's surface, relating the remotely sensed observations to water and temperature conditions at the land surface and upper layers of the soil.
The land surface receives rainfall or irrigation, much of which then flows vertically down through the soil. How fast this water moves depends on the soil properties. In sandy soils, like the ones that are common in Florida, water can move quickly down to the saturated zone, but in richer, clayey soils, water takes longer to move down, and there is more time for roots to absorb the water. When rain falls more rapidly than the ground can absorb and transport it, the water runs over the surface until it finds a stream or a channel.
Soil in the root-zone the most susceptible to heating by the sun, and so there is constant heat exchange. In the day, the upper layer absorbs heat, and in the night, it releases heat. Soil’s capacity to hold heat is not as great as water's, and this is especially true for sandy soils. The day/night temperature change in the upper layer of soil is more extreme than it is at the surface of a lake. Because the soil is warmed during the day, some of water is returned to the atmosphere through evaporation. The plants also release water to the atmosphere through transpiration. In this way, both soil and plant release some of the captured heat back to the atmosphere, and this effect can influence local temperatures and other weather features.
For Judge, the key question is how much fresh water is there in the landscape at a given time. This is central to what the water researchers need as they seek to define how much water is available in a specific area, how it got there, where it goes, how is it stored, and how it transports nutrients and pollutants. Through combining remote sensing and computer models, Judge hopes to “watch” the water and answer these questions for critical regions in a landscape.
Judge describes several approaches to studying the moisture content of the upper soil layer, but the one she prefers using is microwave remote sensing. Judge explains that this method is highly sensitive to changes in soil moisture and makes it possible to bridge the gap between small-scale studies at the field level and larger scale studies at the regional and global scales. Also, microwaves can penetrate vegetation and give a more accurate picture of soil moisture than other wavelengths. Judge says that the 20 cm wavelength (L-band) in the microwave spectrum is best for the studies she conducts. Fortunately, the European Space Agency has launched the Soil Moisture Ocean Salinity (SMOS) sensor in November 2009 which is equipped with an L-band radiometer. The SMOS mission will provide global coverage of near-surface soil moisture every 2-3 days, with 40 km x 40 km resolution. Judge uses similar ground-based active and passive sensors at L-band to produce datasets for developing algorithms to utilize remote sensing observations to their maximum potential. The University of Florida is one of three institutions in the country that has such ground-based sensors and is producing rich datasets during growing seasons of various crops.
Of course, research does not stop with data. As mentioned earlier, Judge uses these datasets to improve hydrologic and crop growth models. As complex as Judge's work can be, it is far from abstract. She focuses on basic research aimed at developing the best understanding and the best tools for understanding soil moisture, but she extends this research through collaborations with researchers whose main interest is the impact of soil moisture. These collaborators include agronomists, foresters, and climate researchers, who all need the very best reading on moisture and heat exchange that they can get. Judge collaborates on wetland models, forest growth models, crop models, and other land cover models.
Judge says that one reason she was eager to come to UF's Agricultural and Biological Engineering department was because of its diversity of specialists and the many engineering disciplines that are represented. Both the Florida Climate Institute and the UF Water Institute, which are strongly represented in the department, find her work valuable. The department provides a ready source of collaborations, though Judge also maintains working relationships with several groups outside UF. She serves as director for the Center for Remote Sensing that was established by an endowment from the Chinese Taipei Committee for the International Commission on Irrigation and Drainage. As part of the endowment, she teaches an annual four-week intensive course in Remote Sensing to delegations from Taiwan.
As if there is not enough data to analyze, Judge is looking ahead to 2015 when NASA will launch the Soil Moisture Active Passive (SMAP) mission. The SMAP satellite is dedicated to providing soil moisture measurements, with a fresh set of global data every 2-3 days, similar to the SMOS satellite, but with a much higher spatial resolution at 9 km. This will allow researchers like Judge to study soil moisture changes in near-real time. Data of this quality and quantity will make possible significant improvements in the many models that use soil moisture, with practical results like better crop yield predictions and better weather prediction. Judge and the next generation of her graduate students have a lot to look forward to.
Dr. Judge specializes in microwave remote sensing; electromagnetics; radiative transfer theory; modeling of land surface processes and biogeochemical cycles for different terrain-type; surface and subsurface hydrology; soil physics and transport mechanisms; linkages between water, carbon, and nitrogen cycle; and micro-meteorology.
- ABE 4034 Remote Sensing in Engineering
- ABE 6035 Advanced Remote Sensing (odd years)
- ABE 6037c Remote Sensing in Hydrology (even years)
- Linking changes in dynamic vegetation to passive microwave remote sensing: Involves development of a microwave emission models to predict brightness signatures for vegetation throughout their growth cycle. These models will be linked to crop-growth models from where they will obtain inputs for plant growth and structure.
- Understanding scaling issues for assimilating remotely sensed data in crop and SVAT models:Involves simulating crop-growth and transport of energy, moisture, and nutrients in the soil at satellite scales to incorporate remotely sensed data for improved estimation of soil and vegetation characteristics. These models will include simulations from mixed pixels.
- Ph.D.Electrical Engineering and Atmospheric, Oceanic, and Space Sciences, University of Michigan, 1999
- M.S.Electrical Engineering, Univ.of Michigan, 1994
- B.S.with highest honors, Physics, Stillman College, 1992
- 2008- present: Associate Professor, Agricultural and Biological Engineering Department, University of Florida
- 2001- 2008: Assistant Professor, Agricultural and Biological Engineering Department, Univ.of Florida
- 2000-2001: Postdoctoral Research Associate, School of Public and Environmental Affairs, Indiana University
- 1992-1999: Graduate Student Research Assistant, Radiation Laboratory, Department of Electrical Engineering and Computer Science, The University of Michigan
Awards and Honors
- ASABE Florida Section Young Researcher 2008
- 2006 Region D Faculty Advisor, Society of Women Engineers (SWE)
- Sigma Xi, Scientific Research Honor Society (1999)
- University of Michigan Rackham Travel Fellowship (1994, 1997, 1998)
- Institute of Electrical and Electronics Engineers (IEEE) Student Travel Grant (1997)
- Fellowship, Sloan Foundation (1996)
- Valedictorian, Stillman College (1992)
- The President’s Award for Academic Excellence, Stillman College (1992)
- Outstanding Achievement in Physics award, Stillman College (1992)
- Int’l Student Honor Award, Stillman College (1992)
Other Professional Activities
- Member, ASEE, 2000-present
- Member, IEEE, 1994-present
- Member, American Geophysical Union, 1994-present
- Member, Society of Women Engineers, 1994-present