The Square Kilometre Array (SKA) project is responsible for developing the SKA Observatory, the world's largest radiotelescope ever built: eventually two arrays of radio antennas - SKA1-Mid and SKA1-Low - will be installed in the South Africa's Karoo region and Western Australia's Murchison Shire, each covering a different range of radio frequencies. In particular SKA1-Mid array will comprise 133 15m diameter dish antennas observing in the 350 MHz-14 GHz range, each locally managed by a Local Monitoring and Control (LMC) system and remotely orchestrated by the SKA Telescope Manager (TM) system. Dish LMC will provide a Graphical User Interface (GUI) to be used for monitoring and Dish control in standalone mode for testing, TM simulation, integration, commissioning and maintenance. This paper gives a status update of the LMC GUI design involving users and tasks analysis, system prototyping, interface evaluation, provides details on the GUI prototypes being developed and technological choices and discuss key challenges in the LMC UI architecture, as well as our approaches to addressing them. In the GUI design task we have adopted a Usage-Centered Design (UCD) approach based on the early involvement of users whose feedback is being iteratively considered in analysis phases, as well as in design and evaluation. An IFML based user interaction modeling approach has been adopted.
The Square Kilometer Array (SKA) project aims at building the world’s largest radio observatory to observe the sky with unprecedented sensitivity and collecting area. In the first phase of the project (SKA1), an array of dishes, SKA1-MID, will be built in South Africa. It will consist of 133 15m-dishes, which will include the MeerKAT array, for the 0.350-20 GHz frequency band observations. Each antenna will be provided with a local monitor and control system (LMC), enabling operations both to the Telescope Manager remote system, and to the engineers and maintenance staff; it provides different environment for the telescope control (positioning, pointing, observational bands), metadata collection for monitoring and database storaging, operational modes and functional states management for all the telescope capabilities. In this paper we present the LMC software architecture designed for the detailed design phase (DD), where we describe functional and physical interfaces with monitored and controlled sub-elements, and highlight the data flow between each LMC modules and its sub-element controllers from one side, and Telescope Manager on the other side. We also describe the complete Product Breakdown Structure (PBS) created in order to optimize resources allocation in terms of calculus and memory, able to perform required task for each element according to the proper requirements. Among them, time response and system reliability are the most important, considering the complexity of SKA dish network and its isolated placement. Performances obtained by software implementation using TANGO framework will be discussed, matching them with technical requirements derived by SKA science drivers.
The SKA Telescope Manager (TM) is the core package of the SKA Telescope: it is aimed at scheduling observations, controlling their execution, monitoring the telescope health status, diagnosing and fixing its faults and so on. To do that, TM directly interfaces with the Local Monitoring and Control systems (LMCs) of the various SKA Elements (e.g. Dishes, Low-Frequency Aperture Array, etc.), exchanging commands and data with each of them. TM in turn needs to be monitored and controlled, in order its continuous and proper operation – and therefore that of the whole SKA Telescope – is ensured. It appears indeed that, while the unavailability of one or more instances of any other SKA element should result only in a degraded operation for the whole telescope, a problem in TM could cause a complete stop of any operation. In addition to this higher responsibility, a local monitoring and control system for TM has to collect and display logging data directly to operators, perform lifecycle management of TM applications and directly deal - when possible - with management of TM faults (which also includes a direct handling of TM status and performance data). In this paper, the peculiarities presented by the TM monitoring and control and the consequences they have on the design of a related LMC system are addressed and discussed.