Brian Gunter
Assistant Professor, Aerospace Engineering Georgia Tech College of Engineering
- Atlanta GA
Brian Gunter's research activities involve various aspects of spacecraft missions and their applications.
Georgia Tech College of Engineering
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Biography
Areas of Expertise
Selected Accomplishments
Visiting Research Fellow, Newcastle University, Newcastle-Upon-Tyne, UK
2011
NASA Earth System Science Graduate Fellowship
2002-2004
Dolores Zohrab Liebmann Graduate Fellowship
2000-2003
NASA Group Achievement Award, GRACE Project Team
2004
Earl Wright Endowed Presidential Scholarship in Engineering
2000-2001
Education
The University of Texas at Austin
Ph.D.
Aerospace Engineering
2004
The University of Texas at Austin
M.S.
Aerospace Engineering
2000
Rice University
B.S.
Mechanical Engineering
1994
Selected Media Appearances
Georgia Tech signs $1.2M deal with Xenesis for satellite optical communications
LaserFocusWorld online
2018-07-10
“We expect to significantly add to the total bandwidth of information that we can get down from space, and the more bandwidth we have, the more information we can exchange and the more value we can get from satellite networks,” says Brian Gunter, an assistant professor in Georgia Tech's Guggenheim School of Aerospace Engineering, who will be leading the project.
Laser-Based System Could Expand Space-to-Ground Communication
Georgia Tech News Center online
2018-06-25
“We expect to significantly add to the total bandwidth of information that we can get down from space, and the more bandwidth we have, the more information we can exchange and the more value we can get from satellite networks,” said Brian Gunter, an assistant professor in Georgia Tech’s Daniel Guggenheim School of Aerospace Engineering who will be leading the project.
The Future is Small
Georgia Tech Research Horizons online
2015-12-02
“Some of the experiments we want to do with the mission, such as the inter-satellite laser ranging, haven’t been done with CubeSats before, so this presents some engineering challenges,” said Brian Gunter, an assistant professor in the Georgia Tech School of Aerospace Engineering who is the principal investigator for the project. “We’re asking these small satellites to do a number of complex tasks, so the details can get complicated, and there are a lot of things we have to get right.”
Selected Articles
Simulated Formation Flight of Nanosatellites Using Differential Drag with High-Fidelity Rarefied Aerodynamics
Journal of Guidance, Control, and DynamicsDaniel S. Groesbeck, Kenneth A. Hart and Brian C. Gunter
2019
The control and utilization of small-satellite constellations and formations are particularly challenging due to the resource constraints involved for nanosatellites. One example of this is the Ranging and Nanosatellite Guidance Experiment (RANGE) mission [1]. This two-satellite CubeSat mission consists of two 1.5 U (1U 10× 10× 10 cm) satellites in a leader–follower formation (see Fig. 1), with the goal of improving the absolute and relative positioning capabilities of CubeSats. The satellites have no onboard propulsion system, and they will rely on differential drag techniques to control their relative position. Each satellite will receive Global Positioning System (GPS) telemetry data and will communicate with the Georgia Tech (GT) ground station via Ultra High Frequency (UHF) transmitters.
Separating Geophysical Signals Using GRACE and High‐Resolution Data: A Case Study in Antarctica
Geophysical Research LettersOlga Engels, Brian Gunter, Riccardo Riva, Roland Klees
2018
To fully exploit data from the Gravity Recovery and Climate Experiment (GRACE), we separate geophysical signals observed by GRACE in Antarctica by deriving high‐spatial resolution maps for present‐day glacial isostatic adjustment (GIA) and ice‐mass changes with the least possible noise level. For this, we simultaneously (i) improve the postprocessing of gravity data and (ii) consistently combine them with high‐resolution data from Ice Cloud and land Elevation Satellite altimeter (ICESat) and Regional Atmospheric Climate Model 2.3 (RACMO). We use GPS observations to discriminate between various candidate spatial patterns of vertical motions caused by GIA. The ICESat‐RACMO combination determines the spatial resolution of estimated ice‐mass changes. The results suggest the capability of the developed approach to retrieve the complex spatial pattern of present‐day GIA, such as a pronounced subsidence in the proximity of the Kamb Ice Stream and pronounced uplift in the Amundsen Sea Sector.
Mass balance of the Antarctic Ice Sheet from 1992 to 2017
NatureBrain Gunter et al.
2018
The Antarctic Ice Sheet is an important indicator of climate change and driver of sea-level rise. Here we combine satellite observations of its changing volume, flow and gravitational attraction with modelling of its surface mass balance to show that it lost 2,720 ± 1,390 billion tonnes of ice between 1992 and 2017, which corresponds to an increase in mean sea level of 7.6 ± 3.9 millimetres (errors are one standard deviation). Over this period, ocean-driven melting has caused rates of ice loss from West Antarctica to increase from 53 ± 29 billion to 159 ± 26 billion tonnes per year; ice-shelf collapse has increased the rate of ice loss from the Antarctic Peninsula from 7 ± 13 billion to 33 ± 16 billion tonnes per year. We find large variations in and among model estimates of surface mass balance and glacial isostatic adjustment for East Antarctica, with its average rate of mass gain over the period 1992–2017 (5 ± 46 billion tonnes per year) being the least certain.
An approach for estimating time-variable rates from geodetic time series
Journal of GeodesyOlga Didova, Brian Gunter, Riccardo Riva, Roland Klees, Lutz Roese-Koerner
2016
There has been considerable research in the literature focused on computing and forecasting sea-level changes in terms of constant trends or rates. The Antarctic ice sheet is one of the main contributors to sea-level change with highly uncertain rates of glacial thinning and accumulation. Geodetic observing systems such as the Gravity Recovery and Climate Experiment (GRACE) and the Global Positioning System (GPS) are routinely used to estimate these trends. In an effort to improve the accuracy and reliability of these trends, this study investigates a technique that allows the estimated rates, along with co-estimated seasonal components, to vary in time. For this, state space models are defined and then solved by a Kalman filter (KF). The reliable estimation of noise parameters is one of the main problems encountered when using a KF approach, which is solved by numerically optimizing likelihood. Since the optimization problem is non-convex, it is challenging to find an optimal solution. To address this issue, we limited the parameter search space using classical least-squares adjustment (LSA). In this context, we also tested the usage of inequality constraints by directly verifying whether they are supported by the data. The suggested technique for time-series analysis is expanded to classify and handle time-correlated observational noise within the state space framework. The performance of the method is demonstrated using GRACE and GPS data at the CAS1 station located in East Antarctica and compared to commonly used LSA. The results suggest that the outlined technique allows for more reliable trend estimates, as well as for more physically valuable interpretations, while validating independent observing systems.
The Ranging and Nanosatellite Guidance Experiment (RANGE)
Small Satellite ConferenceBrian C. Gunter, Byron Davis, Glenn Lightsey, Robert D. Braun
2016
The Ranging And Nanosatellite Guidance Experiment (RANGE) cubesat mission was recently selected for a flight opportunity as part of the Skybox University Cubesat Partnership, with a tentative launch date scheduled for 2016. The RANGE mission involves two 1.5U cubesats flying in a leader-follower formation with the goal of improving the relative and absolute positioning capabilities of nanosatellites. The satellites' absolute positions will be tracked using GPS receivers synchronized with miniaturized atomic clocks, and will be validated using ground-based laser ranging measurements. The relative position of the satellites will be measured using an on-board compact laser ranging system, which will also double as a low-rate optical communication system. The satellites will not have an active propulsion system, so the separation distance of the satellites will be controlled through differential drag techniques. The results of the mission should serve to enable more advanced payloads and future mission concepts involving formations and constellations of nanosatellites. The presentation will give an overview of the mission design and status, as well as the key innovations and expected outcomes.
