Gemini Scripts

The following script makes life easy by not only dithering the telescope, but also by moving the autoguider reticle to keep up with the telescope. Harry Teplitz is to thank for getting the autoguider script commands working properly in a script.

Autoguider scale:
0.37 arcsec/pix in RA (positive telmove in RA corresponds to negative autoguider move)
0.97 arcsec/pix in Dec (positive telmove in Dec corresponds to positive autoguider move)

The useful ranges of reticle positions are:
in RA: 655 (left hand side of guide tv) to 140 (right hand side of guide tv)
in Dec: 20 (top of guide tv) to 150 (bottom of guide tv)

The autoguider reticle positioning only takes absolute pixel positions, which is why the following script starts with the reticle in the middle of the TV guide screen.

Having the center position for the guide reticle is not always useful. The following 3 scripts are identical except for the positions of the guide reticle.
NINE_C.SCR is nearly identical to the script listed below except it pauses only 5 seconds after the telescope moves.
NINE_L.SCR is identical to NINE_C.SCR except the guide reticle starts on the left hand side of the guide tv.
NINE_R.SCR is identical to NINE_C.SCR except the guide reticle starts on the right hand side of the guide tv.


Script to dither the telescope by 13 arcseconds in a 9 position pattern and move autoguider reticle as well. This script was written by Harry Teplitz (with comments added by Elinor Gates).

dth9hit.scr

# Set position of guide reticle in center of TV
autretset 0 350 100
pause 0 'put guidestar in box'

# Take exposure with both chips
go 2

# Move Telescope 13 arcseconds West in RA
telmove -13 0
# Move Autoguider Reticle to new position
autretset 0 385 100
# Wait for telescope to finish moving
pause 10
# Take exposure with both chips
go 2

# Move Telescope 13 arcseconds South in Dec
telmove 0 -13
# Move Autoguider Reticle to new position
autretset 0 385 87
pause 10
go 2

# Move Telescope 13 arcseconds East in RA
telmove 13 0
# Move Autoguider Reticle to new position
autretset 0 350 87
pause 10
go 2

# Move Telescope 13 arcseconds East in RA
telmove 13 0
# Move Autoguider Reticle to new position
autretset 0 315 87
pause 10
go 2

# Move Telescope 13 arcseconds North in Dec
telmove 0 13
# Move Autoguider Reticle to new position
autretset 0 315 100 
pause 10
go 2

# Move Telescope 13 arcseconds North in Dec
telmove 0 13
# Move Autoguider Reticle to new position
autretset 0 315 113
pause 10
go 2

# Move Telescope 13 arcseconds West in RA
telmove -13 0
# Move Autoguider Reticle to new position
autretset 0 350 113
pause 10
go 2

# Move Telescope 13 arcseconds West in RA
telmove -13 0
# Move Autoguider Reticle to new position
autretset 0 385 113
pause 10 'resuming in 10sec'
go 2

#return to center of pattern
# Move Telescope 13 arcseconds East in RA and 13 arcseconds South in Dec
telmove 13 -13
# Move Autoguider Reticle to new position
autretset 0 350 100

# Beep when Done
beep 100


Other popular scripts

There are many scripts available on the Gemini PC already. A few of the more often used ones are listed below.

If you want to alter these scripts (most often you will customize them to your observing program), copy them to another file for editing and don't alter the already existing scripts (this will keep the original script writers and the support scientists happy).

stern6.scr9 position script with full size of dither 20" x 20"
stanford.scr16 point grid, approx. 10" between each grid position
do10.scrDo 10 exposures with each chip, no dithering. Very useful for dark frames.
dark*.scrVarious scripts to do dark frames.
domeflat.scrScript to do dome flats.
sky.scrScript to make sky frames.
mos*.scrMosaic scripts.
nod*.scrNodding scripts.