文档介绍：Optical Interferometry for Fundamental Physics
Michael Shao, Slava G. Turyshev
Jet Propulsion Laboratory, California Institute of Technology
4800 Oak Grove Drive, Pasadena, CA 91009 USA
h L. Nordtvedt, Jr.
Northwest Analysis, 118 Sourdough Ridge Rd.
Bozeman MT 59715 USA
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Stellar Interferometry Applied to Fundamental Physics
The SIM mission is a very high accuracy astrometry instrument, designed to search terrestrial s around nearby stars, as well as conduct a number of astrophysical investigations including the study of dark matter in the galactic disk, halo, and the local group.
pleted its technology program in 2005, a lot of this technology is applicable to missions focused more directly on fundamental physics
Length metrology with single digit eter accuracy
Very precise angle measurements,
This talk will concentrate on the technology needed to measure angles with sufficient precision to measure gamma to ~10-9.
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Earth
Sun
~ 1º
Target spacecraft
t3
t2
t1
DS-Earth  2 AU  300 million km
Reference spacecraft
DR-T  5 million km
Accuracy needed:
Measure:
3 lengths [ t1, t2, t3 ]
Distance: ~ 3 mm
THE LASER ASTROMETRIC TEST OF RELATIVITY
The LATOR Mission Concept
Geometric redundancy enables a very accurate measurement of curvature of the solar gravity field
Accurate test of gravitational deflection of light to 1 part in 109
Euclid is violated in gravity:
1 angle [ ]
International Space Station
Angle: picorad
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What Does a Stellar Interferometer Measure?
External Delay
– Internal Delay
0
Detected
Intensity
An interferometer measures (B·s)  the dot product of the baseline vector & a unit vector to the star,
The peak of the interference pattern occurs when [Internal delay] = [External delay]
Space Interferometry Mission
THE LASER ASTROMETRIC TEST OF RELATIVITY
Internal
Path Delay
or, the projection of the star vector in the direction of the baseline
S
B
Delay line
Detector
biner
telescope 2
telescope 1
External P