Atacama Large Millimeter/submillimeter Array Karl G. Jansky Very Large Array Robert C. Byrd Green Bank Telescope Very Long Baseline Array CASA Progress and Status ANASAC Face-to-Face Sept 16-17, 2013 Jeff Kern CASA Team Lead

ALMA CASA Status CASA is in routine use at ALMA and the VLA for daily operations. – Many other observatories are also using CASA 25% of NRAO CASA Helpdesk tickets are for non-NRAO telescopes Improvement in performance, ease of use, and robustness are being addressed as well as the development of additional features. Reviewed in March: – Report and response available: – Summary: Remain focused on VLA and ALMA needs Improve fundamentals of software engineering process 2ANASAC Face-to-Face: Sept. 16,

ALMA Organization Changes In the process of organizing a new CASA Users Committee to solicit input from a wider segment of the CASA users community. – Details still in progress – Designed to complement the CASA Science Steering Committee (CSSC) not replace. We are working closely with Science User Support (SUS) to do scientific validation of new CASA features prior to release. – Bi-weekly meeting to review test targets, status and assignments DMSG has added a software testing group focused on ALMA testing, including CASA: – Focused on improving automated software testing, not validation. 3

ALMA CASA Usage CASA Releases are downloaded around 2000 times per release – Widely distributed download sites Weak preference for ALMA partners 4

ALMA Performance CASA performance for most tasks is comparable with other packages. – Historical reputation for performance issues still linger. – Are some known poorly performing capabilities (plotting) Parallel CASA has been demonstrated to significantly improve performance. – User interface issues / learning curve have prevented wide acceptance Moving from home grown cluster management to MPI Working with Scientific Computing Infrastructure group to benchmark pipelines and identify performance bottlenecks. MSTransform task introduced: – Allows multiple actions on data with a single read from disk. – Consolidates duplicate code to single maintainable framework. 5

ALMA Performance: Data Access (Disk I/O) Unlike many other aspects of the processing equation, time alone will not solve the data access problem. 6

ALMA Performance Comparison Very simple imaging to try to minimize package variations All tests run on Socorro cluster node against Lustre CASA Review March – 4000 X 4000 pixels – 3000 Components – No Boxing – 0.5 arcsec – Number of Terms = 1 – Single pointing – No Widefield – No A-Term – Briggs weighting 0 Time to Image ~200 GB data set:

ALMA Performance Comparison CASA Review March CASAMIRIADAIPS 1 Major Cycle Serial Major Cycle Threaded 55 5 Major Cycles Serial Major Cycles Threaded Major Cycles Multi-process 74 All times in Minutes

ALMA Infrastructure Initiatives Continued effort on Parallelization, focused on delivery of capabilities to end users/ MSTransform to standardize I/O and decrease overall I/O volume Imager Update – Major re-architecting to improve interface, normalize options, support for new algorithms, regularization. Region Format: Unification and improvement across the package. Tool Documentation: Image tool is current focus, starting to work our way through the package. Imregrid: Major rework for more intuitive operation. SetJy: Reorganized for more clarity in options, scriptability (pipeline), and improved capabilities. 9

ALMA Recent Developments Support for Linear Polarized Feeds (Required for ALMA Cycle-2) Support for rapidly moving objects (Ephemeris Objects) throughout package Simulation update in support of Cycle-2 CFP Improved primary beam handling – Summer student Kara Kundert has extended her project to understand the effects of heterogeneous primary beams on image dynamic range. Single Dish: – Introduction of CalTable like interface (Pipeline Support) – Performance Improvements Feathering: Capability is undergoing continued enhancements 10

ALMA CASA Viewer Many improvements in the CASA viewer – Histogram generation and fitting – Spectral line display and fitting – Position-Velocity Curves – Interface improvements 11

ALMA CASA Viewer Primary View 12

ALMA CASA Viewer: Spectral Line Fitting 13

ALMA CASA Viewer Histogram fitting 14

ALMA ALMA Development Program CASA was very active in the ALMA Development program Studies: – NRAO PI: Interoperability of AstroPy and CASA Projects: – NRAO PI: [Sub-]Millimeter VLBI support in CASA – NRAO PI: Extended On Demand Computing CASA Execution in external environments XSEDE – NRAO CO-I: Post imaging Analytics Development of “value added” products for the pipeline – NRAO CO-I: Next Generation Viewer Collaborating on a Tera-Pixel viewer 15

16 The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc. science.nrao.edu