by John Morgan
Institute of Radio Astronomy, Bologna
IRA Coffee Talk
28 March 2008
l Time 时间
l Baseline 基线
l (channel) 通道
l (polarisation) 偏振极化
l ALMA：The Atacama Large Millimeter/submillimeter Array (ALMA), an international partnership of Europe, North America and East Asia in cooperation with the Republic of Chile, is the largest astronomical project in existence. ALMA will be a single telescope of revolutionary design, composed initially of 66 high precision antennas located on the Chajnantor plateau, 5000 meters altitude in northern Chile.
l EVLA：The Expanded Very Large Array Project: A Radio Telescope to Resolve Cosmic Evolution
l e-MERLIN：The Multi-Element Radio Linked Interferometer Network (MERLIN) is an interferometer array of radio telescopes spread across England. The array is run from Jodrell Bank Observatory in Cheshire by the University of Manchester on behalf of STFC as a National Facility.
n The Joint Institute for VLBI in Europe was formally established in 1993 by the Consortium for VLBI in Europe. The Institute is located in Dwingeloo, the Netherlands, and hosted by ASTRON, the Netherlands Institute for Radio Astronomy.
n The Very Long Baseline Array (VLBA) is an interferometer consisting of 10 identical antennas on transcontinental baselines up to 8000 km (Mauna Kea, Hawaii to St. Croix, Virgin Islands). The VLBA is controlled remotely from the Science Operations Center in Socorro, New Mexico. Each VLBA station consists of a 25 m antenna and an adjacent control building. The received signals are amplified, digitized, and recorded on fast, high capacity recorders. The recorded data are sent from the individual VLBA stations to the correlator in Socorro.
软件相关处理正变得越来越流行。比如国际低频阵列LOFAR（low- frequency acquisition and ranging），运行在IBM的blue gene上。
n Bologna 博洛尼亚
n Cagliari 卡利亚里
n Bonn 波恩
n Spectral-line VLBI
n Wide-field VLBI
n e-VLBI is possible if the correlator is real-time
l DiFX也有pulsar binning 模式
n Can correlate the calibrator first
n Can correlate several times shifting the center of the field
l Collection of software tools
l Designed to give identical output to the VLBA Correlator
l However VLBA observations use different control files