The Graphical User Interface (GUI) is now the de facto standard in the commercial world. It is proposed that all interaction with the ALMA system will be through GUIs, except for the low level scripting that controls the realtime system.
Because GUIs are a fundamental part of the presentation of the instrument, they should be implemented with a common style and reusable components. Many interfaces will be required to the instrument and its data flow for different purposes. Administrative access occurs in the scheduling phase, engineering access during operations, and scientific access during an archive search. This implies that a variety of people using different computing platforms from different locations will access the instrument. As much as possible, the GUIs should support multiple platforms and remote access. All GUIs should have an embedded standardized help system so that documentation is always available.
Support for observing commands and sequences will be handled with an Observing Tool that can produce either scripts or object sequences for the realtime engine. Integration with source catalogs, image databases, and spectral line catalogs are essential to create a high level tool. The Observing Tool can be used by an astronomer to prepare an observing script, or by the telescope operator to produce an updated script for a project.
The correlator complexity presents particular problems that require a GUI for most non-trivial setups. The Correlator Configuration Tool can be run standalone or be invoked by the Observation Tool.
A list of some of the major GUIs can serve as a model for interaction with the data flow. Details of some of these interfaces are found in other sections.