Pattern Data Submission

Description

A slew or dither pattern file can be used to slew the telescope between targets, dither, change exposure times, change filters & the number of exposures.  If a user wishes to simply cycle through a series of filters (without moving the telescope), the input file can be very brief and only include exposure time and filter names. Not all exposure options are allowed in the pattern file, so it is recommended that the user takes one test image with the desired parameters such as binning factor so these values are cached and will be used while the pattern is running.

These pattern files need to be on the observer machines ( dct-obs1 / dct-obs2 ) because they will be input into the LOUI.  All of the caveats for creating Observer Target Lists apply here, such as using a basic text editor (e.g., vi or emacs) and avoiding extended character sets.  You may transfer your pattern files to the observer machines via USB drive or scp, as desired, or even create them directly on the observer machine during the observing session.

Format

Slew-dither pattern files must begin with a metadata line (starting with a #) indicating which fields are present in the file.  Options include:

• title: This will be treated the same as the "Object name" in the LOUI's [LMI / DeVeny / NIHTS ] Control view.
• RA and DEC: Only J2000.0 coordinates are allowed.
• exposureTime: The exposure time in seconds. This must be present.

numExposures: If this is not specified, it will default to 1.

lter: If this is not specified, it will default to whatever lter is in place at the time the sequence

starts.

muRA, muDEC, and epoch: the proper motion (in mas/yr) to be applied and the corresponding

epoch. Note that muRA is really muRA*cos DEC; this is the form that most catalogs (and SIMBAD)

provide.

dRA and dDEC: any non-sidereal rates that need to be applied for tracking. The units are arc

seconds per hour.

rotator PA: By default the rotator PA is set to 0, but there may be occasions where the user would

like a non-standard orientation.

rotator Frame: Either Target or Fixed. This is a rather obscure parameter and we suggest leaving

it at the default.

xi and eta: Rather than provide RA and DEC, it is possible to simply specify tplane osets from

the current position. The osets are in arc seconds, and will be performed as an \absolute" oset.

See Section 4.6.1.

comment: This character string will be to added the header. The comment must be enclosed by

double quotes.

commandOption: This determines if the command is a \slew" or a \dither."

The format to follow is below starting with the metadata at the beginning of the document. This particular example is a dither pattern. More info can be found on the Automated Functions page. Appropriate string names for the filters are listed in LMI Filter Information.

#title=false ra=false dec=false exposureTime=true numExposures=true filter=true muRA=false muDec=false epoch=false dRA=false dDec=false rotatorPA=false rotatorFrame=false xi=true eta=true comment=true
#
60.0  1 SL-g   0.0   0.0  "Centered SDSSg"
120.0 1 SL-r   0.0   0.0  "Centered SDSSr"
120.0 1 SL-i   0.0   0.0  "Centered SDSSi"
60.0  1 SL-g  15.0  30.0  "dXi,Eta = 15,30 SDSSg"
120.0 1 SL-r  15.0  30.0  "dXi,Eta = 15,30 SDSSr"
120.0 1 SL-i  15.0  30.0  "dXi,Eta = 15,30 SDSSi"
60.0  1 SL-g  33.0  -5.0  "dXi,Eta = 33,-5 SDSSg"
120.0 1 SL-r  33.0  -5.0  "dXi,Eta = 33,-5 SDSSr"
120.0 1 SL-i  33.0  -5.0  "dXi,Eta = 33,-5 SDSSi"
60.0  1 SL-g   0.0   0.0  "Centered SDSSg"
120.0 1 SL-r   0.0   0.0  "Centered SDSSr"
120.0 1 SL-i   0.0   0.0  "Centered SDSSi"
60.0  1 SL-g -30.0  15.0  "dXi,Eta = -30,15 SDSSg"
120.0 1 SL-r -30.0  15.0  "dXi,Eta = -30,15 SDSSr"
120.0 1 SL-i -30.0  15.0  "dXi,Eta = -30,15 SDSSi"
60.0  1 SL-g  -5.0 -33.0  "dXi,Eta = -5,-33 SDSSg"
120.0 1 SL-r  -5.0 -33.0  "dXi,Eta = -5,-33 SDSSr"
120.0 1 SL-i  -5.0 -33.0  "dXi,Eta = -5,-33 SDSSi"
60.0  1 SL-g   0.0   0.0  "Centered SDSSg"
120.0 1 SL-r   0.0   0.0  "Centered SDSSr"
120.0 1 SL-i   0.0   0.0  "Centered SDSSi"