On the problem of the HIPPARCOS reference frame

Lattanzi, M. G.; Bucciarelli, B.; Bernacca, P. L.

doi:10.1086/191477

Cited by 3 publications

(2 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Rigid rotations (spins) of SIM's reference frame are parts of the null space of a global astrometric solution (Lattanzi, Bucciarelli & Bernacca 1990;Makarov & Milman 2005), and, therefore, can not be determined from observations with SIM. They are confined to three low-order magnetic vector harmonics, while the vector field of proper motions caused by the secular acceleration is represented by the three electric harmonics of zero and first order.…”

Section: Discussionmentioning

confidence: 99%

Astrometric Effects of Secular Aberration

Kopeikin

Макаров

2006

100

View full text Add to dashboard Cite

One of the main endeavors of fundamental astrometry is to establish a practical realization of an inertial reference frame anchored to celestial objects whose positions are defined in the barycentric coordinates of the solar system. The development of astrometric facilities operating from space at a microarcsecond level of precision makes the non-uniformity of the galactic motion of the barycenter an observable effect that violates the inertiality of the barycentric frame. Most of the observable effect is caused by secular acceleration of the barycenter with respect to the center of the Galaxy. The acceleration results in a pattern of secular aberration which is observable astrometrically as a systematic vector field of the proper motions of distant quasars. We employ the vector spherical harmonics to describe the predicted field of the proper motions and evaluate its amplitude at each point on the celestial sphere. It is shown that the pattern of secular aberration is fully represented by three low-order electric-type vector harmonics, and hence, it is easily distinguishable from the residual rotations of the reference frame and other possible effects, such as the hypothetical long-period gravitational waves. Comprehensive numerical simulations of the grid astrometry with SIM PlanetQuest are conducted. The full covariance matrix of the simulated grid solution is used to evaluate the covariances of the three electric harmonic coefficients, representing the secular aberration pattern of proper motions. We conclude that the grid astrometry with SIM PlanetQuest will be sensitive to the main galactocentric component of secular acceleration, while the peculiar acceleration of the Sun with respect to LSR is expected to be too small to be detected with this astrometric space interferometer.Comment: 21 pages, 4 figure

show abstract

Section: Discussionmentioning

confidence: 99%

Astrometric Effects of Secular Aberration

Kopeikin

Макаров

2006

100

View full text Add to dashboard Cite

show abstract

“…The full covariance matrix could not be computed in Hipparcos, since the adopted solution was not global, but rather a three-step iterative procedure including the adjustment of one-dimensional abscissae coordinates and attitude (great circle reductions), adjustment of reference great circle zero points, and finally, a fit to astrometric parameters over the entire set of the great circle abscissae (sphere solution). The main reason for using this scheme was the practical difficulty of a least-squares solution on a global design matrix of over unknowns 5 6 # 10 ( Lattanzi et al 1990). …”

Section: Introductionmentioning

confidence: 99%

Accuracy and Covariance Analysis of Global Astrometry with theSpace Interferometry Mission

Макаров¹,

Milman²

2005

PUBL ASTRON SOC PAC

View full text Add to dashboard Cite

ABSTRACT.Construction of an all-sky microarcsecond astrometric grid is an essential preliminary step toward global astrometry with the Space Interferometry Mission (SIM). The general setup of the global astrometry problem is given, and fast, robust algorithms to solve the problem are described. The results of extensive numerical simulations are used to outline the conditions necessary to achieve the performance goal of absolute astrometric accuracy. Rigorous computation of the global covariance matrix makes it possible to correctly interpret and utilize the SIM data. We formulate and resolve the new issue of the basic performance uncertainty of a single astrometric mission.

show abstract