The Virgo Gravitational Waves Detector has recently entered its commissioning phase. An important element in this phase is the application of Software Engineering (SE) practices to the Control and Data Analysis Software. This article focus on the experience in applying those SE practices as a simple but effective set of standards and tools. The main areas covered are software configuration management, problem reporting, integration planning, software testing and systems performance monitoring.
Key elements of Software Configuration Management (SCM) are source code control allowing checkin/checkout of sources from a software archive combined with a backup plan. The tool SCVS developed on top of CVS in order to provide an easier and more structured use mode is supporting this.
Tracking bugs and modifications is a necessary complement of SCM. A central database with email and web interface to submit, query and modify Software Problem Reports (SPR) has been implemented on top of the WREQ tool.
Integrating software components that were not designed with integration in mind is one of the major problems in software development. An explicit Integration Plan is therefore absolutely essential. We are currently implementing a slow upgrade cycle Common Software Releases management as structured integration plan.
Software Testing must be closely integrated with development and to the most feasible extent automatic. With the use of the automated test tool tat, the developer can incrementally build a unit/regression test suite that will help measure progress, spot unintended side effects, and focus the development efforts.
One of the characteristics of large and complex projects, like Virgo, is the difficulty in understanding how well the different subsystems are performing and then plan for changes. In order to support System Performance Monitoring the tool Big Brother has been adopted to make it possible to trace the reliability of the different subsystems and thus providing essential information for software improvements.
Two siderostats having 40 cm input pupil have been developed for the early commissioning phase of the VLT Interferometer at Paranal. Performances, design and development of the system are briefly introduced. First results obtained in Europe are discussed.
The Very Large Telescope (VLT) Observatory on Cerro Paranal (2635 m) in Northern Chile is approaching completion in this year when the fourth of the 8-m Unit Telescopes will see first light. At the same time, the preparation for first fringes of the VLT Interferometer (VLTI) is advancing rapidly with the goal of having the first fringes with two siderostats within this year. In this article we describe the status of the VLTI and its subsystems, we discuss the planning for first fringes with the different telescopes and instruments. Eventually, we present an outlook for the future of interferometry with Very Large Telescopes.