Summary of the Fourth ALMA Phasing Project (APP) Commissioning and Science Verification Mission: 2016 April 3-8

Abstract

The primary objectives of the fourth APP CSV campaign were twofold: (1) to execute Very Long Baseline Interferometry (VLBI) observing mode (VOM) observations using Schedule Blocks (SBs); (2) to carry out the first end-to-end testing of intercontinental VLBI sessions in both Bands 3 and 6. While intercontinental VLBI fringes with ALMA have already been obtained during previous CSV campaigns (Matthews & Crew 2016b, c), those sessions were not conducted in a manner identical to future VLBI science campaigns (i.e., they used manual execution of observing commands rather than SBs) and did not involve observations of a full suite of ALMA and VLBI calibrators. Secondary objectives of the fourth CSV mission included further development work on an ALMA Phasing System (APS) graphical user interface (GUI), additional testing of the fast phasing loop (under a wider variety of weather conditions), tests of the phasing system in Band 7 (in support of an ongoing North America ALMA Study award), and the training of ALMA staff in the operation of the VOM and the APS hardware and software. This is a report of the activities of this campaign.