Associate Professor, Department of Aerospace Engineering and Engineering Mechanics
Fellow of the FSX Professorship in Space Application and Exploration
Email: srinivas@csr.utexas.edu
Work: +1 512 471 7587
Mail Code: R1000
Curriculum Vita
Education
Ph.D., The University of Texas at Austin
Research Interests
- Orbital Mechanics, Perturbations, and Orbit Determination
- Space Geodesy (Earth’s Shape, Orientation & Gravity Field)
- Modeling, Determination and Interpretation of Gravity Field
- Space Mission Design
- Data Processing and Numerical Methods
The Earth is very dynamical object – its shape, orientation and mass distribution change on time-scales of days to millenia, driven by physical process in the ocean, the atmosphere, the ice and in the solid Earth. These dynamical processes can be studied from space, using radiometric and laser measurements, together with sophisticated models for the orbital motion of artificial satellites. Dr. Bettadpur’s core interests are the design and architecture of space missions for this purpose; the analysis of space geodetic data; and the interpretation of the results.
Dr. Bettadpur is an Associate Fellow of the AIAA, and a Fellow of the IAG.
Recent Awards and Honors
General Research Interests
Space Geodesy and Spaceflight Mechanics; Earth System Science from space.
Current Research Thrusts (March 2017)
Some are mature, others are nascent – all of these feature dynamics, modeling, estimation and interpretation…
- Dynamics of the Earth system from satellite gravity measurements
- Solve the challenges of mass flux estimation, validation and interpretation in near real-time
- Use of the global, space-based methods to solving problems at the smallest regional scales
- Best representation of gravity information for diverse Earth sciences & applications
- What does this tell us about the dynamics of the Earth system?
- Orbit Determination and Global Space Geodesy
- Can we achieve the 1-mm precision orbits? How can we even tell?
- Multi-technique mm-level positioning and global reference frames
- Regional Applications of Global Methods
- Using remote sensing for understanding the water cycle in Texas and northern Mexico
- A Gulf of Mexico reference frame for natural (inundation) hazards
- How do we apply tomorrow’s technologies for space-based gravity & Earth system science?
- Use of laser interferometry, cold-atom technologies, precise clocks, drag-free flight, etc…
GRACE Follow-On (http://gracefo.jpl.nasa.gov/) – This joint NASA/GFZ mission, to be launched around Jan 2018, carries a laser interferometer in addition to the microwave inter-satellite ranging system. Our research here pertains to the near-real time and definitive gravity field estimation, modeling and interpretation of the mission data. We also carry out mission design and trade studies, as the mission moves towards its launch.
GRACE (http://www2.csr.utexas.edu/grace/) – This joint NASA/DLR mission, in its 15th year of operation as of 2017, has provided unprecedented insights into the entire Earth system. Research continues on the methods to improve the resolution and accuracy of the mean and time-variable Earth gravity models; and on developing innovative new applications.
GSFC/Drought & Flood – This collaboration with Matt Rodell (Hydrological Sciences Branch at GSFC) deals with the use of GRACE and GRACE-FO data with the lowest possible latency, tuned for North American flood and drought applications.
Cold-Atom Technology & Space Geodesy – This JPL-SURP grant with Sheng-wey Chiow at Caltech/JPL looks at the application of cold-atom technology to modern space geodesy problems, like the estimation of the Earth gravity field.
mm-Metrology at McDonald Observatory – This new NASA-ROSES grant, which will last through the year 2018, is looking at mm-precision laser metrology to aid the realization of next generation terrestrial reference frames.
OGMOC – With this collaboration with TU-Munich and DTU, lasting through mid-2017, we are looking at optimal combination of GRACE and GOCE data for the purpose of obtaining the best estimates of geostrophic ocean currents using satellite altimetry and the geoid
Water Cycle in Texas & Northern Mexico – In collaboration with MAGIC group at (UTCSR), we are expanding research into the joint use of GRACE/GRACE-FO, NDVI (from MODIS), precipitation and other available remote sensing resources for the characterization and understanding of the water cycle in Texas and Northern Mexico. A post-doc joined in 2016, and is helping us take this to the next phase of expansion.
Following projects concluded recently, but my hope is that the accomplishments from these projects will lead to more interesting work in these areas in the future.
- Bangladesh & GRACE – This collaboration with Mike Steckler (LDEO/Columbia University) is winding down, and led to us testing the smallest spatio-temporal resolutions to which water loads could be meaningfully extracted from the GRACE data.
- Drag-Free Systems for Satellite Gravity – A collaboration with David Wiese (JPL), this project is wrapping up a study on the specification of requirements for a drag-free system for next generation gravity field measurement missions. The outcomes should inform future space mission design studies.
Spring 2017
ASE 366L – Applied Orbital Mechanics
This is the second class in Orbits at UT ASE/EM, following upon ASE 366K. We now explore the more practical and advanced orbit design topics for space applications. We move past two-body orbits to the oblateness and drag perturbations. We look in detail at the relative geometry of the terrestrial observer on a rotating Earth, the satellite, and the Sun, including topics such as scene, illumination, shadow, etc. We spend reasonable time on relative motion, as modeled using C-W equations. Other topics include brief introduction to GPS and the three-body problem.
ASE389P2 – Satellite Geodesy
This graduate class covers the dynamic Earth and what we may understand about it with space-based methods. The few weeks on positioning covers what we may learn about Earth through the measurement of its kinematics using precise positioning space geodetic techniques. A survey of the Earth orientation, and the dynamics of the elastic Earth and polar motion is provided. Most of the class deals with potential theory, including the expression of the geopotential in spherical harmonics; the study and application of the geoid; Kaula’s theory of orbital perturbations; and time-variable gravity and its orbital effects.
Spring 2016
- ASE 366L – Applied Orbital Mechanics
- ASE 389P.4 – Methods in Orbit Determination
The list of my students since 2010, and links to their theses, should give you a good idea of the scope of work that has kept my group busy for the past several years.
PhD
Sakumura, C (2016) – On GRACE data assimilation in land surface models
Bonin, J (2010; co-supervised) – On high-frequency information content in GRACE data
Save, H (2009; co-supervised) – On the regularization of the gravity field estimation problem
MS
Fulcher, R (2016) – On the thermal characteristics of GRACE satellites
McWilliams, H (2015) – On the validation of the 1-cm orbit for LEO satellites
McCandless, S E (2014) – On the multi-sensor data fusion for drought monitoring from GRACE
McCullough, C (2013) – On the numerical methods for next generation gravity missions
Sakumura, C (2013) – On the ensemble averaging of gravity field solutions
Krishnan, S (2012) – On the empirical reconstruction of accelerations from orbits
Pini, A (2012) – On the role of ground track repeats and GRACE data quality
Benegalrao, S (2012) – On the sensitivity analysis of attitude control systems
Projects content to go here….