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|Title: ||High-precision early mission narrow angle sciene with the Space Interferometry Mission|
|Authors: ||Shaklan, S.|
Milman, M. H.
|Issue Date: ||22-Aug-2002 |
|Citation: ||Astronomical Telescopes and Instrumentation|
Waikaloa, HI, USA
|Abstract: ||We have developed a technique that allows SIM to measure relative stellar positions with an accuracy of 1 micro-arcsecond at any time during its 5-yr mission. Unlike SIM's standard narrow-angle approach, Gridless Narrow Angle Astrometry (GNAA) does not rely on the global reference frame of grid stars that reaches full accuracy after 5 years. GNAA is simply the application of traditional single-telescope narrow angle techniques to SIM's narrow angle optical path delay measurements. In GNAA, a set of reference stars and a target star are observed at several baseline orientations. A linearized model uses delay measurements to solve for star positions and baseline orientations. A conformal transformation maps observations at different epochs to a common reference frame. The technique works on short period signals (P=days to months), allowing it to be applied to many of the known extra-solar planets, intriguing radio/X- ray binaries, and other periodic sources. The technique's accuracy is limited in the long-term by false acceleration due to a combination of reference star and target star proper motion. The science capability 1 micro-arcsecond astrometric precision - is unique to SIM.|
|Appears in Collections:||JPL TRS 1992+|
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