The goal of this project is to identify high-density plasma formed in the lower ionosphere due to lightning in order to understand the effects on ground-to-satellite RF communication. In particular, we are deploying co-located lightning and ionospheric arrays in New Mexico in order to understand the mechanism for generating sporadic-E during thunderstorm activity. Our array consists of a suite of lightning ground-based RF receivers at VLF and VHF, and 4 HF transceivers covering 1-30 MHz that allow 6 oblique cuts through the ionosphere. These data are then incorporated into 4-D inversion algorithms that allow for sub-km resolution of the lower ionosphere.
Sigrid Close
Prof. Close's research involves space weather detection and modeling for improved spacecraft designs, and advanced signal processing and electromagnetic wave interactions with plasma for ground-to-satellite communication systems. These topics fall under the Space Situational Awareness (SSA) umbrella that include environmental remote sensing using satellite systems and ground-based radar. Her current efforts are the MEDUSSA (Meteoroid, Energetics, and Debris Understanding for Space Situational Awareness) program, TALIS (Tomographic Array for Lightning and Ionospheric Studies) using ground-based and space-based RF sensors, and using ground-based radar data to characterize the meteoroid population and its threat to spacecraft. Future work includes using CubeSats for asteroid detection and characterization.
Last modified Mon, 14 Jan, 2013 at 23:06
| Title | Author(s) | Journal |
Date |
|---|---|---|---|
| Analysis of Perseid meteor head echo data collected using the Advanced Research Projects Agency Long-Range Tracking and Instrumentation Radar (ALTAIR) | Close et al | Radio Science | 08-2000 |
| Astronomical and physical data for meteoroids recorded by the ALTAIR radar | Brown et al | Proceedings from Meteoroids 2001 | 08-2001 |
| Two-frequency meteor observations using the Advanced Research Project Agency Long Range Tracking and Instrumentation Radar (ALTAIR) | Hunt et al | Proceedings from Meteoroids 2001 | 08-2001 |
| Interpretation of non-specular radar meteor trails | Dyrud et al | GRL | 08-2002 |
| Characterization of Leonid meteor head echo data collected using the VHF-UHF Advanced Research Projects Agency Long-Range Tracking and Instrumentation Radar (ALTAIR) | Close et al | Radio Science | 08-2002 |
| A technique for calculating meteor plasma density and meteoroid mass from radar head echo scattering | Close et al. | Icarus | 11-2003 |
| Meteor velocity determination with plasma physics | Dyrud et al | Atmospheric Chemistry and Physics, | 08-2004 |
| Determination of the meteoroid velocity distribution at the Earth using high-gain radar | Hunt et al | Icarus | 08-2004 |
| A new method for determining meteoroid mass from head echo data | Close et al | JGR | 08-2005 |
| Interstellar Meteors | Baggaley et al. | Workshop on Dust in Planetary Systems (ESA SP-643) | 08-2005 |
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NSF CAREER award (2011-2016)
Elected Vice Chair Commission G (URSI)
Arecibo Science Advisory Panel
National Research Council Aeronautics and Space Engineering Board Micrometeoroid and Orbital Debris Panel Member
Hellman Faculty Scholar 2010
Meteoroids 2010 Scientific Organizing Committee
National Research Council Aeronautics and Space Engineering Board Review of Near-Earth Object Surveys and Hazard Mitigation Strategies Mitigation Panel Member
Planetary Decadal Survey Interplanetary Dust
Cover of IEEE Spectrum 2008
1st Place Student Paper Competition International Union of Radio Science
Exceptional Efforts in Meteoroid Impact Study
Joe D. Marshall Award presented by AFTAC for Outstanding Technical Briefing
MIT Lincoln Scholar
TALIS: Tomographic Array for Lightning and Ionosphere Studies
QB50
Prof. Close is leading the American effort for the QB50 project run by the von Karman Institute for Fluid Dynamics. These 50 CubeSats will be used to measure lower thermospheric properties.
MEDUSSA: Meteoroid, Energetics, and Debris Understanding for Space Situational Awareness
The focus of this program is to detect and model meteoroid impacts on spacecraft in order to understand the properties of hypervelocity particles and their damage mechanism through both mechanical and electrical effects. The data include both ground-based hypervelocity impact tests, and in situ impacts of hypervelocity impacts and a modeling component that encompasses electromagnetic emission from dense plasmas. We are currently designing the MEDUSSA spacecraft, which is a CubeSat containing RF, optical and silicon detectors aimed at characterizing the electromagnetic pulse formed upon meteoroid impact. We are also conducting experiments at the Max Planck Institute for Nuclear Physics in Germany in order to characterize the plasma and RF from a hypervelocity impact on a satellite.
Interplanetary Dust and Meteoroids
We are investigating the origins and impacts of interplanetary dust in order to drive the science and engineering missions for the next decade. Primarily we use high-power, large-aperture radars around the world to detect and characterize the plasma formed when a meteoroid enters into Earth's atmosphere. Our students are working with radars in southern Argentina, the Kwajalein Atoll in the Pacific Ocean, the Jicamarca radar in Peru, the MIT Millstone Radar in Massachusetts, and the Arecibo Radar in Puerto Rico. These projects also include modeling and simulation using the latest Particle-in-Cell (PIC) techniques.
