LIRIS software

LIRIS
Long-slit Intermediate Resolution Infrared Spectrograph for the WHT

INSTRUMENT CONTROL

The instrument control will be carried out by several software subsystems. A main user interface with the instrument support platform (ISP), which provides the means for controlling all LIRIS subsystems. The following subsystems will be accessible:

Observing Program Preparation Tool: It will be used by astronomers at their home institution to create observing sequences. It also contains a basic instrument simulator to compute expected S/N ratios for the different observing modes. It should facilitate access to whole sky standard catalogues, such as POSS, 2MASS, IRSKY.
Templates Scripts Software: This system is used to generate the LIRIS observing templates. It will have a set of predefined observing modes or templates, each of them with a set of configurable parameters (exposure time, reading modes, pointing offsets). This system will generate sequence of commands which can be interpreted by the ISP.
Instrument Support Platform User Interface: This will be the main user interface for the instrument. It would allow to interact with the telescope control software and hopefully with the autoguider software.
LIRIS Mechanism Control Software: This system can receive commands from the Instrument Support Platform and return status information. It comprises the following 2 subsystems:
LIRIS EPICS Mechanism Control Software: This system is the responsible of the direct control of the LIRIS mechanisms (slit, filter, pupil, grism, camera wheels and detector focus). This software will run on the VME EPICS rack.
Temperature Controller Software: This system will be used to control and monitor the detector temperature.
Real Time Display: This system is used to monitor the newly acquired images. It will provide some facilities as basic image statistics, different ways of image scaling, plus a seeing and background monitor.
Quick Look Data Analysis: This system will provide facilities for a quick analysis of the acquired data. This should include sky subtraction, alignment of images, extraction of spectra, default wavelength calibration.
Pipeline Processing: This system will be used ot process blocks of data. The following processing steps will be done: sky subtraction, flat-fielding, coaddition and alignment of image, in the spectroscopy mode the wavelength calibration will also be included.

OBSERVING TEMPLATES

There is a plan to provide a set of templates to facilitate the observation. These templates should be sufficient to cover most of cases. LIRIS Observing Templates (LOT)

Name	Purpose	Description
Obs_img_Dither	Imaging of point sources or uncrowded fields	There is no need to take separate sky observations. The telescope offsets automatically (dithering) or using a list of specified positions within a box smaller than the camera field of view.
Obs_img_Boff	Imaging of extended sources or crowded fields	Sky observations have to be taken separately. The sky positions can be randomly chosen or from a list. Object positions can be selected as in template Obs_img_Jitter
Obs_spec_Nod	Spectroscopy of point or compact objects	Telescope moves between two positions along the slit for a number of cycles. The two positions can be fixed (beam-switching) or including random offsets around them.
Obs_spec_Boff	Spectroscopy of extended objects	Telescope moves by large offsets perpendicularly to the slit direction.
Obs_img_Polarimetry	Imaging polarimetry
Obs_spec_Polarimetry	Spectropolarimetry
Obs_cal_Gen	Calibration sequences	Flat field, photometric calibrations.

REAL TIME DISPLAY

The Real Time display is used to monitor the image adquisition. It is based on a graphical interface which allows to control the way of displaying images (scaling, sky subtraction) and show basic statistics. The images are displayed using existing facilities such as Ximtool or SAOtng.

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Last modified: 08/03/02

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