Specification

Description

Observatory Control System (OCS)

The Observatory Control System of Talon consists primarily of Xobs, the Linux X-Windows based observatory control program.  This program calls upon and coordinates much of the interrelated portions of the Talon architecture, and forms the primary control panel for the telescope, dome, and peripheral systems when used locally. 

Remote users accessing the system will be presented with a web-browser display, incorporating much of the same information as is found in Xobs, but presented in a somewhat different style more appropriate to the medium.   This functionality is provided by Claw.

Logging of critical system functions is performed by Talon for diagnostic and technical review purposes.  This information chronicles the operation of the observatory subsystems at a component and driver level.

Telescope Control System (TCS)

The telescope control software of Talon supports the controlled, properly accelerated and damped slewing of the telescope to target (manually or automatically) and subsequent tracking of the target.  Tracking is supported by a pointing mesh (calibration) that is created by preparing a survey of the sky and performing precise WCS solutions at each of these sampled locations.  The encoder-to-actual error is recorded for each position and is then used as interpolation points for any subsequent pointing operation.  This results in a very good and very repeatable pointing accuracy

Instrument Control System (ICS)

The Instrument Control System controls the primary CCD camera, filter wheel, guide camera and focus mechanism. 

Access to the controls for the Instrument Control System is through Xobs as implemented by Talon, and by similar interfaces in Claw, as well as the scheduling options available via Claw.  Locally, images captured by the system may be viewed using Camera, a comprehensive CCD camera controller, image viewer, and analysis tool.  Web based users have the option of downloading their images for offline processing, or for simple viewing in web-delivery format.

Both standard and H-compressed FITS files are supported.  All relevant FITS fields are noted for each exposure, including location, time, exposure, image scale, object, and WCS solution, among others.

Dome Control System (DCS)

Documentation for interface and configuration options to the dome enclosure are provided with Talon.  The control system for the dome is governed by a CSIMC controller, which runs a script that handles basic dome operational commands.  These CSIMC functions can be easily adapted to control nearly any type of switch interface to a dome control system.

The Dome Control Software handles all aspects of the dome function including rotation, shutter open/close, and rotation to shutter power.  Optical Mechanics has adapted Talon for use with domes from a variety of manufacturers.

Environmental Control System (ECS)

Weather station monitors for barometric pressure, temperature, humidity, precipitation, wind speed and direction are standard in Talon.  The Davis Instruments EZ Mount Weather Monitor II or equivalent is provided.

Scheduler Manager System (SMS)

Development of the Claw product includes creation of a scheduling solution that addresses most common user needs. 

The scheduler as delivered accepts observing requests from users.   The basic components of an observation request consist of naming the object or coordinates to view, the equipment to be used including filter choice, and the exposure time.  Other specialized options, such as scheduling a fixed location (non tracking) exposure, or shutter ‘flashing’ (used in determining streak direction) may also be selected.

Direct Internet Control System

Users with appropriate privileges can request direct control sessions and are entered into the scheduler as fixed blocks of time.  The user for whom the direct control session has become active is allowed to sign into the system for remote control at any time during this session block.  As with any observation, the system will prohibit the use of the telescope equipment during unfavorable weather conditions.  Administrators may override a direct session, in the same way that they might override a scheduled request.