National Radio Astronomy Observatory June 13/14, 2005 EVLA Phase II Proposal Review EVLA Phase II Computing Development Bryan Butler (EVLA System Engineer for Software)

National Radio Astronomy Observatory 13/14 June, 2005 EVLA Phase II Proposal Review EVLA Software The primary goals of EVLA software are: maximize the scientific return of the EVLA; be easy to use, for all astronomers; provide a look-and-feel and functionality which is consistent with all NRAO telescopes.

National Radio Astronomy Observatory 13/14 June, 2005 EVLA Phase II Proposal Review EVLA Phase II Computing The EVLA Phase II computing effort: Develops software, by the end of the construction project, which can be used for accessing or operating those parts of the EVLA telescope included in Phase II (E configuration; NMA; use of WIDAR for VLBA correlation); turns this software over to Operations - there is therefore a close relationship between software development (by the EVLA Phase II project) and operation, maintenance, and upgrade (by Operations); Mostly a simple extension of EVLA Phase I software effort.

National Radio Astronomy Observatory 13/14 June, 2005 EVLA Phase II Proposal Review EVLA Software - Methodology 1.Scientists deliver use cases and requirements; 2.Overall design developed based on these; 3.Each subsystem with the overall design then developed in greater detail; 4.For all three of the above, iterate with short cycles (as short as a week, depending on the particular item).

National Radio Astronomy Observatory 13/14 June, 2005 EVLA Phase II Proposal Review Overall NRAO Design (e2e) Telescope Data Model Export Data Format Science Data Model Feedback to telescope Proposal Submission And Handling Observation Preparation EVL A VLBAALM A GBT EVLA Sched EVLA Control ALMA Sched ALMA Control GBT Sched GBT Control Data Capture Archive Telcal OfflineVO Observer Domain Mostly Telescope- Independent Common Software VLBA Sched VLBA Control Quick Look Pipeline GBT Postproc Telescope Domain Science Domain Mostly Telescope- Specific Project Software Mostly Telescope- Independent Common Software

National Radio Astronomy Observatory 13/14 June, 2005 EVLA Phase II Proposal Review Overall EVLA Design (1) Observation Preparer Astronomer Default Program Block (with ‘suggestions’ filled in) One Program EVLA Observing Heuristics Program Block (Set of Scheduling Blocks for one Program) Refinements Proposal Preparer To Observation Scheduler Observer Domain

National Radio Astronomy Observatory 13/14 June, 2005 EVLA Phase II Proposal Review Overall EVLA Design (2) Telescope Domain Observation Scheduler Observation Executor Hardware M&C Next SB Execution State Equipment State Metadata to DCAF Operator Environment From Observation Preparer Results from TelCal Sequence of Configurations Antenna Delays Archive Operator Raw Visibility Data Properties Data Addressing Info Equipment State Archive Operator Heuristics Metadata to DCAF To DCAF To Archive

National Radio Astronomy Observatory 13/14 June, 2005 EVLA Phase II Proposal Review Overall EVLA Design (3) Science Domain Quick Look Pipeline Astronomer Observation Monitor Image Cubes SDM Archive Post-Processing Image Cubes Astronomer Default Image Pipeline Image Cubes Data Capture And Format From M&C TelCal To DCAF & Executor SDM Archive

National Radio Astronomy Observatory 13/14 June, 2005 EVLA Phase II Proposal Review Phase II Specific Developments The major developments for EVLA Phase II are: Additional hardware to support much higher archive data rates; Software to schedule the WIDAR correlator to support VLBA recorded media, and simultaneously correlate EVLA, NMA, and/or VLBA; Post-processing system development in support of the much higher resolution full EVLA and NMA.

National Radio Astronomy Observatory 13/14 June, 2005 EVLA Phase II Proposal Review Archive Data Rates Expected data rates are determined by computing the dump time necessary to avoid time-bandwidth smearing. We know however that we cannot support the highest rates immediately (in 2014), so we have a staged plan, to allow storage (and processing) speeds to catch up: We do not expect these rates to be difficult to support (they are quite conservative), given current storage capabilities and expected increases, and in fact we may increase at a faster rate. Date Max Data Rate (MB/s) Total Volume (TB/yr) 2008 (Phase I)

National Radio Astronomy Observatory 13/14 June, 2005 EVLA Phase II Proposal Review Scheduling At the completion of Phase II we will have 37 antennas which must be flexibly scheduled in various combinations. The software must support this, which will require changes to most of the subsystems. All are minor, except the Observation Scheduler. In addition, we plan to use the WIDAR correlator to correlate VLBA disk-recorded observations, and to concurrently correlate combinations of all of the possibilities. This will require development of new software, including a Correlator Scheduler subsystem.

National Radio Astronomy Observatory 13/14 June, 2005 EVLA Phase II Proposal Review Post-Processing Effort in several areas of post-processing is needed, but much of this development is common with either ALMA or EVLA Phase I or both. The primary issue is the sheer size of the databases and the computational load. We estimate the following CPU power necessary: This is not trivial, but we do not see it as a major problem. Date Average CPU rate TFlop normalized * compute power 2008 (Phase I) * - normalized by assuming doubling every 18 months (Moore’s Law), and scaling to the 2008 compute power. This implies 125 GFlop right now.

National Radio Astronomy Observatory 13/14 June, 2005 EVLA Phase II Proposal Review Post-Processing Recent changes: major reorganization; rewrite of code base (CASA) and interface (Python); development driven by ALMA and EVLA deliverables; ALMA already incorporating outside users in testing, EVLA planning to do so soon.

National Radio Astronomy Observatory 13/14 June, 2005 EVLA Phase II Proposal Review Post-Processing - Details Use of a common post-processing package is the baseline plan for all three of ALMA, EVLA Phase I, and EVLA Phase II. We understand that there is some skepticism that NRAO can successfully develop such a post-processing package, given recent past performance. We point out, however, the following salient features of the new post-processing package: the project has undergone a major reorganization, including the disbanding of the AIPS++ consortium and replacement of top level management; the code base is undergoing a massive rewrite (the CASA libraries are the result), with a revised interface based on Python instead of glish; development is now based upon project needs for ALMA and EVLA, including a coherent testing plan (for both ALMA and EVLA) which incorporates NRAO staff scientists and external users, and responds to deliverables based on requirements provided by the projects. Because of these changes, we are confident that the post-processing package can deliver what is necessary for our processing needs. This is not to say that there are no remaining problems - just that they are not insurmountable.

National Radio Astronomy Observatory 13/14 June, 2005 EVLA Phase II Proposal Review Personnel (1) 61.5 FTE years budgeted: Observer Domain - Total = 7.5 Proposal Observation Preparation Telescope and Correlator Scheduling Telescope Domain - Total = 21.5 E configuration Other (MIBs, Executor, VLBA antenna rewrite, etc…) Correlator Backend Using WIDAR for VLBA Science Domain - Total = 29.5 Post-processing Data Archiving Pipelines Computing Infrastructure - Total = 3.0

National Radio Astronomy Observatory 13/14 June, 2005 EVLA Phase II Proposal Review Personnel (2) We can do this with only 61.5 FTE years (which would seem too small for a project of the size of EVLA Phase II) because of: heritage from EVLA Phase I - with ~100 FTE years of effort; overlap with ALMA - with ~250 FTE years of effort. In this way, just as we are leveraging EVLA Phase I hardware (which leveraged VLA hardware) we are also leveraging the software.

National Radio Astronomy Observatory 13/14 June, 2005 EVLA Phase II Proposal Review Hardware Budget In addition to the 61.5 FTE years of effort, there is ~$2M budgeted for computing hardware. This includes: networking upgrades; pipeline hardware; M&C (CBE and CALC) hardware; Post-processing hardware: Development cluster; Final cluster; Observers workstations; Data storage and distribution media.

National Radio Astronomy Observatory 13/14 June, 2005 EVLA Phase II Proposal Review Summary EVLA software is designed to: maximize the science derived from the instrument; be easy to use, for all astronomers; provide a look-and-feel and functionality which is consistent with all NRAO telescopes. It builds extensively on the foundation of Phase I; There are three main areas specific to Phase II: Scheduling - telescope and correlator; Archive (mostly hardware); Post-processing FTE years and ~$2M hardware budgeted, with ~100 FTE years and $2M hardware leveraged from Phase I; some part of ~250 FTE years leveraged from ALMA.