On the Geodetic Feasibility of Mars with VLBI Observables from Mars Probe
Based on the observation of Mars probe with ground VLBI, the observation model including the position of Mars probe and connection parameters of reference systems is studied in this paper, and the estimable parameter sequence is determined. Then the adjustment method appropriate for rank defect in the matrix of normal equation coefficients is studied, the model parameters are calculated and their precisions are evaluated. Thirdly, the impact of accidental errors to the parameters is analyzed. The results are given at the end of the paper.
Relativistic VLBI Delay Model for Finite Distance Radio Source
When very long baseline interferometry (VLBI) is applied to observation of finite distance radio source from observer and the curvature of the the wave front cannot be approximated as plane wave. Thus current standard VLBI model (‘Consensus model’) does not have enough accuracy and an alternative precise VLBI delay model for finite distance radio source corresponding to the ‘Consensus model’ is required in observation of radio source in the solar system (e.g. planets, asteroids, and spacecraft). We derived a formular of relativistic VLBI delay model for finite distance radio source by taking into account coordinates transformation by using linearized PPN metric. This model is valid in order of several pico seconds accuracy when the radio source is at distance beyond 109 m. Our model include the ‘Consensus model’ as a special case that radio source is at infinite distance form the observer.
IERS Conventions (2003)
Abstract : This document is intended to define the standard reference systems realized by the International Earth Rotation Service (IERS) and the models and procedures used for this purpose. It is a continuation of the series of documents begun with the Project MERIT Standards (Melbourne et al., 1983) and continued with the IERS Standards (McCarthy, 1989; McCarthy, 1992) and IERS Conventions (McCarthy, 1996). The current issue of the IERS Conventions is called the IERS Conventions (2003). When referenced in recommendations and articles published in past years, this document may have been referred to as the IERS Conventions (2000). All of the products of the IERS may be considered to be consistent with the description in this document. If contributors to the IERS do not fully comply with these guidelines, they will carefully identify the exceptions. In these cases, the contributor provides an assessment of the elects of the departures from the conventions so that its results can be referred to the IERS Reference Systems. Contributors may use models equivalent to those specified herein. Products obtained with different observing methods have varying sensitivity to the adopted standards and reference systems, but no attempt has been made in this document to assess this sensitivity. The reference systems and procedures of the IERS are based on the resolutions of international scientific unions. The celestial system is based on IAU (International Astronomical Union) Resolution A4 (1991). It was officially initiated and named by IAU Resolution B2 (1997) and its definition was further refined by IAU Resolution B1 (2000). The terrestrial system is based on IUGG Resolution 2 (1991). The transformation between celestial and terrestrial systems is based on IAU Resolution B1 (2000).