Robotic Control
 

TJO has multiple science cases to cover, including transient phenomena. This kind of multipurpose observatory requires the capability to change the observatory scheduling in real time and maximizes its efficiency by locating the decision taking capability in a control system developed to work without human interaction.

Telescope operations

Most of the processes included in the science observation and calibration task routines are executed without human interaction.

The tasks supported by the observatory and handled by the robotic control system are:

  • Science observations. The proposals submitted to the observatory define a set of science observations to obtain images and data in order to fulfill a specific science case.
  • Calibration tasks. Calibration processes are necessary to reduce the data obtained with the science observations. A nominal set of calibration images per instrument are routinely taken.
  • Safety. Appart from taking exposures, security of the observatory is ensured through a set of ancillary systems resposible to monitor the environment and the hardware operations.
  • Housekeeping. In order to mainain a robust software architecture and to guarantee the data flow, several systems are regularly monitored and checked.

Control layers and workflow

The control system of the observatory works in a fully unattended manner, or specifically under robotic control, for most of the data flow processes. Only the proposal submission and the data retrieval requires human interaction. The control system is based on three main layers:

  • End-to-end data flow control layer. This software layer is in charge of executing all the data acquisition routine, from user proposal submission to user data retrieval, and includes data processing feedback for the optimization of the operation scheduling.
  • Monitor layer. This software layer is in charge of monitoring the system health, all the environment sensors and the support devices.
  • Physical layer. It contains the hardware elements of the system. It is composed by the science devices to acquire astronomical data (telescope, dome, and instruments), the environment sensors and other support devices for housekeeping purposes.

End-to-end dataflow control

Several applications are used to run the processes required for the observatory operation control: OpenROCS, ISROCS, ICAT and DDROCS. They all together compose a software suite called the Robotic Observatory Control System (ROCS), designed and developed in a modular way to be adaptable to a different hardware layout and, thus, to other robotic observatories. They are all developed at IEEC.

  • MUR. Science observations are entered into the system by submitting a proposal to the observatory using the Management for Users in ROCS (MUR) web application. The procedure to submit a proposal is described in the MUR help page.
  • OpenROCS. The Open Robotic Observatory Control System (OpenROCS) is the core element of the control system. The execution of a science observation or a calibration task includes the monitoring and control of all the hardware involved (telescope, instrumentation and dome) and monitoring of the environment data. Regarding hardware control, it includes pointing and tracking, filter and focus positioning, image acquisition, and housekeeping tasks that ensures the system safety in case of bad weather conditions. These processes are all handled by OpenROCS with specific calls to low level software (TALON, SNMP commands, etc.). OpenROCS is a master scheduler of the processes that the system has to execute and a monitor of the overall state of the observatory. It controls the end-to-end data flow and the housekeeping processes by handling a set of predefined events. The former are responsible for ensuring that the system executes the routine operation by maximizing the scientific return of the facility. While the latter consider all those anomalous situations that could put the observatory at risk and activate corrective or mitigation actions. All the applications running at the TJO observatory and the hardware components interact with it. OpenROCS conforms an independent layer that can be exported to other robotic observatories. It is released under GNU/GPL public license.
  • DDROCS. The TJO database, called the Dynamic Database for the Robotic Observatory Control System (DDROCS), is devoted to store the proposal details in a way to optimize the flux of data from submission to retrieval by user.
  • ISROCS. An automatic scheduling routine (ISROCS, standing for Intelligent Scheduler for the Robotic Observatory Control System) selects the most suitable task/s to be performed by the observatory, according to predefined criteria and with the goal of maximizing the time invested in science operations.
  • ICAT. Every time a new science or calibration image is acquired, an on-the-fly process for its reduction and analysis is executed. A quality check is then performed to determine if the image is obtained in compliance with predefined criteria, and to provide feedback to the observatory control system. Images and data extracted are finally stored. The IEEC Calibration and Analysis Tool (ICAT) was developed for these purposes and it is used to provide high quality data to the users.

Generalitat de CatalunyaUniversitat de BarcelonaUniversitat Autònoma de BarcelonaUniversitat Politècnica de CatalunyaConsejo Superior de Investigaciones CientíficasCentres de Recerca de Catalunya