NRAO contributions to the VSOP mission

Abstract

The National Radio Astronomy Observatory (NRAO) is a participant in the VSOP Space VLBI mission, an international collaboration led by Japan's Institute of Space and Astronautical Science (ISAS). The Observatory's contributions fall in six main areas, all developed and operated with support from the National Aeronautics and Space Administration (NASA). NRAO has committed 30% of scheduled observing time on the VLBA, and smaller allocations of time on other NRAO instruments, to joint observations with the VSOP mission's Halca spacecraft. NRAO also provides tracking of Halca, including downlinking and recording of the observations, at an earth station at NRAO's Green Bank site. The VLBA correlator is committed for processing of any VSOP observations involving NRAO ground-based telescopes. About 75% of all General Observing Time scientific observations have been processed at the VLBA correlator. The Astronomical Image Processing System (AIPS) was also modified to accommodate a number of unique features of Space VLBI observations. Most of the images derived from VSOP observations have been produced using AIPS. NRAO has integrated Space VLBI observing into routine VLBA operations, and operates a regional user support facility to assist US-based astronomers in analysis of VSOP observations.