Nordic Optical Telescope

TCS SEQUENCER Script Reference

Note that the optional -e flag invokes "do-nothing" mode, which only displays the to-be-executed TCS commands on the terminal.

tcs.setup-tel-alfosc [-e]
Sets up the telescope for observing with ALFOSC.
Currently equivalent to the commands:

Note that the last command prepares the telescope to put horizontal slits onto the parallactic angle.
To prepare the telescope for vertical slits please execute the command

tcs.setup-tel-alfosc

tcs.setup-tel-fies [-e]
Sets up the telescope for observing with FIES.
Currently equivalent to the commands:

tcs.setup-tel-mosca [-e]
Sets up the telescope for for observing with MOSCA.
Currently equivalent to the commands:

tcs.setup-tel-notcam [-e]
Sets up the telescope for observing with NOTCam.
Currently equivalent to the commands:

tcs.setup-tel-stancam [-e]
Sets up the telescope for normal imaging with STANCAM.
Currently equivalent to the commands:

tcs.guide-object [-f fieldrotation] objectname

tcs.guide-object-with-parallactic objectname

tcs.guide-object-with-fixed objectname

tcs.store-tel <filename>
Saves current TCS settings, to be restored later with tcs.restore-tel .
The data file will be stored in the current working directory. If the file already exists, it will be overwritten.
tcs.restore-tel [-e] [-noconfirm] <filename>
Restores saved TCS settings, stored by tcs.store-tel .
The data will be read from file <filename> in the current working directory.
If the store file is more than 10 hours old, a warning will be issued, but the script will continue.
Interactive confirmation is prompted for, except when the -noconfirm flag is given on the command line.
If a stored value is different from the current DB value, then the appropriate restoring TCS command will be issued from the Sequencer.
In order for the TCS to accept changes for certain parameters, this script switches off autoguiding, and leaves it off.
Note that several restored parameters will be reset by the TCS at the next preset:
- tv-focus
- equatorial-offset
- horizontal-offset
- guide-probe-position
which implies that this script has to be rerun after presetting if these parameters need to be restored properly.
Currently uses the following commands to restore the settings:
- tcs.tcs-command "Rotator-Manual"
- tcs.tcs-command "Rotator-Automatic"
- tcs.field-rotation
- tcs.tcs-command "Equatorial-Offset"
- tcs.tcs-command "Horizontal-Offset"
- tcs.focus-position
- tcs.focus-delta
- tcs.auto-positioning-off
- tcs.tcs-command "Auto-Positioning-Semi"
- tcs.auto-positioning-full
- tcs.guide-probe-position
- tcs.tv-focus
- tcs.tv-filter
- tcs.tcs-command "Star-Box-Quadrant-Size"
- tcs.star-box-position
- tcs.tcs-command "Background-Box-Quadrant-Size"
- tcs.background-box-position
- tcs.instrument-parallactic-angle
- tcs.tcs-command "Instrument-Name"
- tcs.offset-size
- tcs.probe-step-size
- tcs.camera-probe-park
- tcs.camera-probe-fies
- tcs.camera-probe-stancam
tcs.reposition-guide-probe [-e] ra-rate dec-rate
Wrapper script to start differential tracking/guiding or to re-start differential guiding when the star-box has reached the limit. This is for fast-moving targets observed with differential tracking and guiding, with the star-box moving across the guide-TV screen.

- tcs.ag-off
- tcs.box-motion-stop
- tcs.optimal-box-position-for-moving-objects ra-rate dec-rate
- tcs.box-motion-start ra-rate dec-rate
- tcs.tcs-command "Move-Guide-Probe-To-Put-Star-In-Box"

If/when the star-box approaches the edge of the screen before your observation has finished, you can re-position the guide probe to its optimal starting position by running this script in another sequencer window than your observing script. Note that the input parameters ra-rate and dec-rate must be given as dRA/dt and dDEC/dt in the units "/hour.

The re-positioning of the guide probe typically takes 4 seconds and should not affect the position of the telescope, which will continue with the differential tracking on the target (i.e. the set-rate is given when box-motion-start is applied, but not reset with box-motion-stop). There is a limit to how many times you can re-position depending on the starting position of the guide probe, the rotator position and the ra-rate/dec-rate of the target.
tcs.diff-tracking-rates [-e] ra-rate dec-rate
Wrapper script to set differential tracking without autoguiding, using the following commands:

- tcs.ag-off
- tcs.tcs-command "set-rate ra-rate dec-rate"
tcs.differential-to-sidereal-guiding [-e] (to be tested)
Wrapper script to switch from differential tracking/guiding to sidereal tracking/guiding on the same target, using the following commands:

- tcs.ag-off
- tcs.tcs-command "set-rate 0 0"
- tcs.box-motion-stop
- tcs.ag-relaxed-on

NB! Will only work if you are already autoguiding!

tcs.asteph [-e] [-t asteroid|comet|planet] [-m ima|para|along-slit|optimal-ll|optimal-lr] [-r full|half] -n object_name

Interactive Asteroid Ephemeris script that connects to the JPL Horizons database and searches for coordinates and tracking rates of the given object_name for the current UT time at the La Palma observatory. Note that the RA-rate output by Horizons in the form (cos(DEC))*dRA/dt is translated to the simple dRA/dt (''/h) required by the NOT TCS, which applies the cosine(DEC) correction internally.

      The input parameters in [] are optional.
      
       -t default type is "asteroid"
          option "planet" selects for instance the Jovian satellite Europa instead of the asteroid Europa
          option "comet" 
       -m default mode is "ima" using the default field rotation for imaging 
          option "para" for spectroscopy orients the slit along the parallactic angle
          option "along-slit" orients the slit along the tracking direction of the target
          option "optimal-ll" orients the field to  maximize the number of guide-probe repositions
          option "optimal-lr" 180 degrees rotatated to above, both recommended for fast targets or long observations
       -r default tracking rate is "full"         
          option "half" gives the half-rates of the differential tracking (sometimes requested)
       -n \"target name\" is mandatory (if it contains a space, use escape double quotes)

Currently, the result is output on the screen in the form of the NOT sequencer commands needed in order to point to this target (now!) and set up the telescope for differential tracking and guiding, for instance:

       tcs.append-object 2017_TC1-xxxx 20 02 53.11 +27 52 40.6 2000.0 0.0 0.0 20.06
       tcs.ag-off
       tcs.guide-object 2017_TC1-xxxx
       tcs.reposition-guide-probe -750.856 -353.934

Note that you can alternatively use guide-object -f field-rotation or guide-object-with-parallactic etc. Depending on the modes chosen in asteph, the output will adjust the guide-object commands.

Note also that if the target is super fast and you can not guide, use tcs.diff-tracking-rates with the same input differential rates as output from the tcs.asteph command.

tcs.pointing108 [-e] (staff only)
Records pointing accuracy from 108 stars, chosen from the GSC catalog in steps of az=30,alt=8, forming an equidistant grid.
The script is fully automatic, and takes around 1.5 hour to complete.
The pointing data recorded are used to compute a new pointing model (not included in the script).
tcs.pointing216 [-e] (staff only)
Records pointing accuracy from 216 stars, chosen from the GSC catalog in steps of az=15,alt=8, forming an equidistant grid.
The script is fully automatic, and takes around 3 hours to complete.
The pointing data recorded are used to compute a new pointing model (not included in the script).

Last modified: July 02 2024