Software for the Green Bank Telescope GBT Future Instrumentation Workshop September 7, 2006

1. Software for the Green Bank Telescope GBT Future Instrumentation Workshop September 7, 2006 Amy Shelton (ashelton@nrao.edu)

2. Scope & Resources • 8 software engineers, 1 co-op, 1 manager; GB and CV • Control System (incl. new instrumentation), Observing System, Data Analysis, and R&D Support; Operational Support (for observing and data analysis), Maintenance, New Development • Science Drivers: • Enable high-frequency operation of the telescope (PTCS project, instrumentation) • Provide capabilities to generate new, unique science from the GBT • 6-week development cycles in place since 2003 (software only) and since 2004 (site-wide) • New capabilities released after small, iterative rounds of integration testing (to ensure integrity of new code within system), regression testing (to ensure continuity of existing observational capabilities), and sponsor testing (scientific validation of new functionality).

3. How is Our Software Organized? GUIs Application Application Component 0..n uses Expert User uses HLAPIs Programmer uses LLAPIs Control System Observed Data (in an EDF) Real-Time Data (streaming)

4. How is Our Software Organized?

5. The GBT M&C System: Ygor • The Ygor system has been designed for control and monitoring of the many pieces of hardware that make up the GBT. • Hierarchical: Coordinators & Managers • Each device on the GBT has a Manager, i.e. each receiver, each backend, etc. • Each Manager has control capabilities – Parameter • Each Manager has monitoring capabilities – Sampler • Each Manager produces alarms/messages – Message • Managers can produce engineering FITS files – FitsIO • Ygor API: Control and monitor interface to the telescope as defined by the C++ classes Panel and Monitor. • The goal of this interface is to provide everything an observer needs and most of what an engineer or operator needs to interact with the telescope. • Currently accessible directly by C++ classes through Panel and Monitor, by Glish's ygor class (used for debugging only), the enhanced tcl interpreter segeste (used by engineer’s and operator’s interface), and Grail (used by observer’s interface).

6. The GBT M&C System: Ygor

7. Interface Control Requirements to M&C • There is a programmatic interface to the system. This interface may be via software protocols such as class linkage or module or Ethernet communications. A user interface is not considered to be a programmatic interface. • All settings (hardware or software) for a scan are described in a finite set of static variables, i.e., variables only need to be set once, prior to a scan. • Synchronous subsystems (subsystems which internally change state aligned to the start of a scan) start a scan according to a given time. • Synchronous subsystems can provide their earliest guaranteed scan start time on demand prior to a scan, but before acting on the commanded variables.

8. The Observer’s Interface: AstrID • The Astronomer's Integrated Desktop (Astrid) is a single, unified workspace that incorporates, but does not replace, the suite of applications that can be used with the GBT. • Observation Management - Observing API, a.k.a. Turtle • Provides access to source information, antenna motion, configuration, and IF balancing via Scheduling Blocks (SBs). • Scheduling Blocks contain an observing script and project metadata, which allows them to be archived and managed as descriptions of the observer's intent. The Observation Management application component helps you organize your Scheduling Blocks for a project, select and submit them to the telescope, and review what occurred during execution. • Real-time Data Display, a.k.a. GFM • Provides sub-scan-based display and analysis of GBT data, either in real-time as the data is being collected, or in an offline mode where it can be used to simply step through the sub-scans from an observation. • GBT Status Display • Displays various GBT specific parameters, sampled values and computed values. • Product Page: http://wiki.gb.nrao.edu/bin/view/Data/AstronomersIntegratedDesktop

9. The Observer’s Interface: AstrID

10. GBT Data Reduction: GBTIDL • GBTIDL is an interactive package for reduction and analysis of spectral line data taken with the Green Bank Telescope (GBT). • The package consists of: • A set of straightforward yet flexible calibration, averaging, and analysis procedures (the "GUIDE layer") modeled after the UniPOPS and CLASS data reduction philosophies, • A customized plotter with many built-in visualization features • Data I/O and toolbox functionality that can be used for more advanced tasks. • GBTIDL makes use of data structures which can also be used to store intermediate results. • Expert users can also access a toolbox of functions and procedures that operate on a lower level. Although this seems to happen rarely. • The package consumes and produces data in GBT SDFITS format. Observers have uncalibrated SDFITS data available to them at the end of a run. • GBTIDL can be run online, and have access to the most recent data coming off the telescope, or can be run offline on preprocessed SDFITS files. • Easily allows user-contributed functionality. • Product Page: http://gbtidl.sourceforge.net

11. GBTIDL: GBT Data Reduction

12. Plans for FY2007 • New devices go into service this fall: • Penn Array receiver • Zpectrometer • Dynamic Scheduling of GBT time. • Improvements to SDFITS (our single dish FITS file production program) • Support & enhance of GBTIDL capabilities • Support for Precision Telescope Control System (PTCS) project • One major control system upgrade • Reduce inter-scan latencies • Unified messaging • Creation of data streams