1. Atacama Large Millimeter/submillimeter Array Expanded Very Large Array Robert C. Byrd Green Bank Telescope Very Long Baseline Array Meeting Summary Richard Prestage FAST discussion meeting, CV, 23 July 2010

2. Agenda Areas of Mutual Interest Possible Mechanisms of Collaboration Next Steps after This Meeting 2

3. Areas of Mutual Interest - I – “Next Generation GUPPI” – digital backends Collaboration may be larger than just NRAO/FAST (i.e. Berkeley, Arecibo) Data acquisition and analysis “all in one” backends (inc VLBI and SETI) Could just extend CASPER collaborative framework? Facility instruments versus “expert user” instruments (this is something NRAO brings to the table). – RFI Shielding and Mitigation (including RFI excision) NRAO staff to assist in FAST designs, assist with surveys, develop training materials FAST Engineers to work at Green Bank Mutual development of active RFI excision? (and pulsar algorithms) 3

4. Areas of Mutual Interest - II – Metrology / Alignment / Panel Setting and Adjustment (not critical now) Choosing the Ruler (or other devices; inclinometers, quadrant detector) Using the Ruler – GBT expertise in conventional surveying / panel setting – Control Systems Middleware / Infrastructure Telescope Control Distributed Control Systems (Actuators) – high priority for FAST High Speed Data Acquisition – lower priority for FAST – Offline Data Processing. NRAO is looking for collaborations, but ones where the collaboration overhead is low. Be aware of what each side is doing. Pulsar Search Algorithms / Pattern Recognition Spectroscopy data reduction (as data rates/volumes increase) Science-specific pipeline developments 4

5. Areas of Mutual Interest - III IF / Data Transmission over Optical Fiber – High priority for NRAO and FAST Current FAST baseline is analog transmission Area where NRAO may assist FAST. Lightweight, integrated receivers Might buy from NRAO? Interested in < 1GHz, combined with w/b feed Consider conceptual design/feasibility study? Phased Array Feeds Main purpose for FAST is to dynamically illuminate variable area For later; FAST will follow NRAO development progress Wideband feeds (combined with integrated rx) Telescope Beam Pattern Calculations – not priority now (later discussions with rx group) FAST wants to know actual beam pattern in use Could compare FAST / NRAO calculations 5

6. Possible Collaboration Mechanisms - I Joint Development of New Instrumentation – FAST Scientist and Engineers and NRAO Scientists and Engineers collaborate to develop new instrumentation Next Generation Pulsar Backend using latest CASPER technology L-band Phased Array Feed – Each group pays for their own specific hardware – Share development and resulting designs 6

7. Possible Collaboration Mechanisms - II FAST staff visit NRAO sites – Scientists and/or Engineers – Periods of six months to two years? – Work on topics of mutual interest (e.g. pulsar search off-line data processing, distributed software development) – Work is done primarily by FAST personnel, but with guidance and support of NRAO personnel – Science collaborations – Student exchanges (both ways) 7

8. Possible Collaboration Mechanisms - III NRAO staff visit FAST Sites – Engineers and/or Scientists – Timescales of ~one week to a few months – NRAO staff assist with a specific activity (e.g. surveying) NRAO build Instrumentation for FAST Need to agree compensation mechanisms 8

9. Other topics Consider 3 or 4 400MHz feeds (100MHz bandwidth), looking at spherical surface for drift scans – pulsar searching with very simple backends. HI drift scans may also acquire high sensitivity, high resolution data. EOR at low frequency (RFI may be an issue). Simple is best! 9

10. Summary / Next Steps 1.We have identified a wide range of areas of mutual interest – Need to identify one or two very well-defined, very specific areas to pursue in more detail GUPPI / pulsar data processing algorithms RFI Analog/digital fiber development and data transmission 2.Need to agree specific mechanisms for collaboration (refine MOU?) – Probably a few specific individuals from either side? 3.Seek specific additional funding opportunities (e.g. US Collaborative Funding Programs, e.g. PIRE and others, Chinese funding from CAS). 4.Once (1) and (2) in place; further discussions to set up implementation 10