The paper presents astrometric work at the Max Planck Institute for Radioastronomy. A program of Very Long Baseline Interferometer (VLBI) observation of Love numbers, continental drift, and earth rotation variations to determine the positions of compact extragalactic radio sources, and observations to evaluate the use of phase in VLBI-astrometry are described. A hydrogen maser has been implemented as a frequency standard at the Effelsberg observatory which will improve accuracy by 2 orders of magnitude over the rubidium standard. A project to incorporate phase to reach the ultimate positional accuracy with VLBI techniques, and an investigation of the positional accuracy of the new model fitting routine was made with a number of blind tests on a noise-free two component model. The experiments aim at observing pairs of radio sources with simple nuclear structures to obtain their relative positions to ultimate accuracy.
IAU Colloq. 48: Modern Astrometry
- Pub Date:
- Radio Astronomy;
- Very Long Base Interferometry;