Engineering topics
Giorgini, J. D.
Publications and source records attributed to Giorgini, J. D..
Improved Impact Hazard Assessment with Existing Radar Sites and a New 70-m Southern Hemisphere Radar Installation
Add radar capability to the existing southern hemisphere 70-m Deep Space Network (DSN) site at Canberra, Australia, thereby increasing by 1.5-2x the observing time available for high-precision NEO trajectory refinement and characterization. Estimated cost: approx.$16 million over 3 years, $2.5 million/year for operations (FY09).
Multi-Wavelength Observations of 2100 Ra-Shalom: Radar and Lightcurves
We conducted a multi-wavelength campaign to study the near-Earth asteroid (NEA) 2100 Ra-Shalom during its August 2003 encounter. Rotationally resolved observations were acquired at Arecibo (12.6 cm radar), the IRTF (0.8-2.5 micron and 3 micron), McDonald Observatory (0.48-0.92 micron), Palomar Observatory (8-15 micron), and Ondrejov Observatory (optical lightcurves). Our objectives were to determine Ra-Shalom's size and shape, and the composition and physical state of its near-surface material. Preliminary results from radar and lightcurve measurements will be presented here.
Direct detection of the Yarkovsky effect by radar ranging to ateroid 6489 Golevka
Radar ranging from Arecibo, Puerto Rico, to the 0.5-kilometer near-Earth asteroid 6489 Golevka unambiguously reveals a small nongravitational acceleration caused by the anisotropic thermal emission of absorbed sunlight. The magnitude of this perturbation, known as the Yarkovsky effect, is a function of the asteroid's mass and surface thermal characteristics. Direct detection of the Yarkovsky effect on asteroids will help constrain their physical properties, such as bulk density, and refine their orbital paths.
Asteroid 1950 DA's encounter with Earth in A.D. 2880
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Radar reconnaissance of potentially hazardous asteroids and comets
Groundbased radar is uniquely able to reduce uncertainty in trajectories and physical properties of near-earth objects. Radar can prevent the loss of a newly discovered object caused by the normal decay of orbit knowledge prior to the next optical observing opportunity, can add decades or centuries to the interval over which close Earth approaches can accurately be predicted, can significantly refine collision probability estimates that are based on optical astrometry alone.
NASA's near-Earth object program office
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Asteroid 1950 DA's encounter with Earth in 2880: physical limits of collision probability prediction
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Asteroid Radar Astronomy at the Dawn of the New Millennium
This talk will use images, movies, and radar-derived three-dimensional models to present recent highlights of asteroid radar research, concentrating on low-V mission candidates. Additional information is contained in the original extended abstract.
Radar Discovery and Characterization of Binary Near-Earth Asteroids
The radar instruments at Arecibo and Goldstone recently provided the first confirmed discoveries of binary asteroids in the near-Earth population. The physical and orbital properties of four near-Earth binary systems are described in detail. Additional information is contained in the original extended abstract.
Arecibo Radar Observations of Near-Earth Asteroids: A Study in Heterogeneity
Characterization of the rotation state and structure of near-Earth asteroids through radar observations using the Arecibo and Goldstone planetary radar systems shows the remarkable variety of these objects, and suggests variety of formation and modification mechanisms. Additional information is contained in the original extended abstract.
A global solution for the gravity field, rotation, landmarks and ephemeris of Eros
This solution uses the entire one-year in orbit collection of X-band radiometric tracking (Doppler and range) from the Deep Space Network and landmark tracking observations generated from the NEAR spacecraft images of Eros.
Radar observations of asteroid 25143 (1998 SF36)
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Orbit uncertainty and close-approach analysis capabilities of the horizons on-line ephemeris system
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Sentry: an automated close approach monitoring system for near-Earth objects
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