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Geodesy Technology Innovation


The Summer 2022 issue of CuttingEdge (A NASA GSFC periodical dedicated to emerging technologies) features work by Scott Luthcke (61A) and partners on the gravity-measuring Atom Interferometer Gravity Gradiometer (AIGG) in an article entitled "Satellite Geodesy – Innovation Born at Goddard" (pp. 7–9).

The Atom Interferometer Gravity Gradiometer, developed in partnership with the Fremont, California-based AOSense, offers the potential for accurate, direct, real-time measurement of Earth’s gravitational field and its changes over time. Scott Luthcke and Goddard physicist Babak Saif (Code 551) led development of the gravity-measuring technology, which works by pulsing a laser through a cloud of super-cooled atoms. Measuring the laser’s interaction with the atoms creates an interference pattern. Scientists know how the atoms should be-have at a quantum level, so the interference serves as a real-time measurement of gravity’s pull on the atoms.

Shortest Day Gets Attention

Stephen Merkowitz (61A) was recently interviewed by media outlets such as the Associated Press, The World on Public Radio, and Verify for articles about the recent shortest length of day on record. Measurements of the Earth’s length of day are performed daily by the Space Geodesy Project as part of NASA’s participation in the National Earth Orientation Service.

NASA Space Geodesy Project Hosts Summer Interns


The NASA Space Geodesy Project hosted seven interns over the summer: two high school students, four undergraduates, and one graduate student. Six interns were partly or completely virtual, one was onsite; These interns worked with different scientists and engineers of the of the Space Geodesy Project over the summer (June - August 2022) on projects related to Very Long Baseline Interferometry (VLBI) or Lunar Laser Ranging (LLR).

The interns and their projects were:
  • Josh Wu ( Texas Academy of Math & Science ). Project: “Modeling RF Notch Filter to Predict 20K Insertion Loss and Rejection”. NASA Mentors: Lawrence Hilliard (NASA SGP VLBI Technologist) & Jeffrey Dorman (NASA SGP Operations Manager).
  • Joseph Conaty ( Eleanor Roosevelt High School, Greenbelt, Maryland ). Project: “Cryo STEM: Radio Frequency Monitoring System (RFMS) Graphical User Interface (GUI).” NASA Mentors: Lawrence Hilliard (NASA SGP VLBI Technologist) & Jeffrey Dorman (NASA SGP Operations Manager).
  • Simon Matin (University of New Mexico). Project: “Avoiding Spaceborne Radio Frequency Interference for Astronomical Observations”. NASA mentors: Dr. Nlingi Habana (SAIC@ Code 61A) & Lawrence Hilliard (NASA SGP VLBI Technologist).
  • Joshua Batstone ( University of Maryland, College Park ) Project: "Star image Analysis for Lunar Laser Ranging (LLR)" Worked both virtually and onsite with NASA Mentor Evan Hoffman (Code 61A), and Dr. Russet Macmillan ( Apache Point LLR Observatory, New Mexico) to develop improved software to aid in the calibration of star images for use at Apache Point during LLR.
  • Joseph Skeens. ( University of Texas at Austin): Project: “Automated detection of spurious signals in VLBI phase calibration data”. Worked onsite with NASA mentor, VLBI scientist Leonid Petrov (Code 61A) as an SAIC summer intern. Joe is a Ph.D Student at the University of Texas at Austin, and his advisor is Dr. Srinivas Bettadpur.
  • Ludvig Rodung & Tuss Anzelius ( Chalmers University, Sweden), hosted in Greenbelt by NVI inc. Project: “Deriving gaussian models for (radio) sources”. Worked with John Gipson (NVI @ Code 61A, NASA GSFC), IVS Analysis Coordinator and leader of the NVI VLBI group for the NASA Space Geodesy Project.
We hope the in situ and virtual experiences were enjoyable for the interns. All the interns who were in the Greenbelt area were at some time able to interact in person with the NASA scientists, and also visit the Goddard Geophysical and Astronomical Observatory (GGAO) . The GGAO is one of the handful of sites in the world that hosts all four geodetic techniques, and is critical for the maintenance of the International Terrestrial Reference Frame (ITRF).
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The laboratory performs broad research, in the areas of Earth time variable and static geopotential and geomagnetic fields, Earth orientation, surface deformation, characterization and change, tides, land ice mass evolution, global and regional sea level, and airborne and spaceborne laser altimetry. The laboratory also supports many NASA missions in fundamental and core capabilities including satellite radar and laser altimetry precise positioning, pointing, ranging, timing, geolocation and calibration and validation. The laboratory is a leader in the design, development, implementation and application of airborne and spaceborne geodetic laser altimeter technology and instruments including NASA’s Land, Vegetation, and Ice Sensor (LVIS) and the Global Ecosystem Dynamics Investigation Lidar (GEDI). The laboratory is the home of the Space Geodesy Project which encompasses the management, development, operation and maintenance of NASA’s Space Geodetic Network that is comprised of the four major space geodetic observing systems: Very Long Baseline Interferometry (VLBI), Satellite Laser Ranging (SLR), Global Navigation Satellite System (GNSS), and the Doppler Orbitography and Radio-positioning by integrated Satellite (DORIS) system. It is also home to the Crustal Dynamics Data Information System dedicated to the archive and distribution of space geodesy related data sets; as well as the home to GEODYN, NASA’s state-of-the-art geodetic parameter estimation and precision orbit determination system.

For further information, data, research, and other resources, see Geodesy and Geophysics Projects.

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Dr. Bryant D. Loomis
Chief [61A]
Evan Derek Hoffman

General inquiries about the scientific programs at NASA's Goddard Space Flight Center may be directed to the Center Office of Communications at 1.301.286.8955.

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