The Potential for a Ka-band (32 GHz) Worldwide VLBI Network

Christopher S. Jacobs, Jet Propulsion Laboratory, California Institute of Technology/NASA, Uwe Bach, Max-Planck-Institut fuer Radioastronomie, Francisco Colomer, Instituto Geografico Nacional, Cristina Garcia-Miro, Madrid Deep Space Communications Complex, INSA/NASA, Jesus Gomez-Gonzalez, Instituto Geografico Nacional, Sergei Gulyaev, Institute for Radio Astronomy and Space Research, Auckland University of Technology, Shinji Horiuchi, Canberra Deep Space Communications Complex, CSIRO/NASA, Ryuichi Ichikawa, Kashima Space Research Center, NICT, Alex Kraus, Max-Planck-Institut fuer Radioastronomie, Gerhard Kronschnabl, Bundesamt fuer Kartographie und Geodaesie, Jose Antonio Lopez-Fernandez, Instituto Geografico Nacional, James Lovell, University of Tasmania, Walid Majid, Jet Propulsion Laboratory, California Institute of Technology/NASA, Tim Natusch, Institute for Radio Astronomy and Space Research, Auckland University of Technology, Alexander Neidhardt, Technische Universitaet Muenchen, Chris Phillips, CSIRO Astronomy and Space Science, Richard Porcas, Max-Planck-Institut fuer Radioastronomie, Andres Romero-Wolf, Jet Propulsion Laboratory, California Institute of Technology/NASA, Ladislao Saldana, ITT Mission Systems, Ulrich Schreiber, Bundesamt fuer Kartographie und Geodaesie, Ioana Sotuela, Madrid Deep Space Communications Complex, INSA/NASA, Hiroshi Takeuchi, ISAS/JAXA, Joseph Trinh, Jet Propulsion Laboratory, California Institute of Technology/NASA, Anastasios Tzioumis, CSIRO Astronomy and Space Science, Pablo de Vicente, Instituto Geografico Nacional, Vladimir Zharov, Sternberg State Astronomical Institute

Ka-band VLBI capability now exists, is under development, or is being considered at 20 sites around the world. Thus, there is now an opportunity to create a worldwide Ka-band VLBI network. This paper will examine the potential for a cooperative network capable of high resolution imaging and astrometry. Initial fringe tests on a few individual baselines have been successful and more tests are planned. With baselines approaching a Giga-lambda, a Ka-band network would be able to probe source structure at the nano-radian (200 $mu$as) level and thus gain insight into the astrophysics of the most compact regions of emission in active galactic nuclei.