Alternatively, without exiting the TCS session, you can enter the TCS command "COMMS DRAMA" and then start the TELD task separately (log in to LPAS4, choose OPTIONS and then TELD).
Test Drama communications by sending SYS> cmd TCS USER PAGE
and make sure that the Infodisp page changes. If it doesn't work, enter "COMMS DECNET", then "COMMS DRAMA" and test again.
This method of switching may cause an error message on the navis screen.
Guiding packets come from the AO loop, specifically from drift found in the Fast Steering Mirror (FSM), which takes out pupil motion (also called Tip-Tilt) .Since there is no guiding when the AO loop is open, you don't need to turn AUTOGUIDE OFF, even when re-acquiring (unless AO loop has crashed).
The guide star can be the target itself ("self-referencing"), if the latter is sufficiently bright and sufficiently pointlike (< 1.5 arcsec, say, to be smaller than the sub-aperture guide boxes on the wavefront sensor). The guide star cannot be brighter than V = 4, or K ~ 5, because of saturation of the wavefront sensor or science detector respectively. There should be no stars of similar magnitude within ~ 5 arcsec of the guide star, to avoid confusing the wavefront sensor.
Telescope focus 98.60 (Feb 2011):
Measured on the acquisition TV, then subtract a fixed value.
Alternatively, a change of focus expands/contracts the Shack-Hartmann spot pattern, which should fit exactly into the WFS grid.
Determine rotator center:
Not done by TO. A pickoff mirror inside NAOMI can be accurately positioned at the optical rotation axis of the Nasmyth focus.
Normal - on the acquisition TV. A good pointing model will give good tracking, which always helps.
>startobssys choosing correct option for INGRID+NAOMI (+ISIS+...)
This spawns all the necessary command windows, mimics and applications. The main novelties are the commands "dither", "loop open/close" and "rmode".
Dithering is carried out using Craige Bevil's application ("dither"), carrying out a run at different telescope positions. The script opens the AO loop before moving the telescope, and it also moves the AO "pickoff" mirror (a probe in NAOMI focal plane, which feeds to the WFS) in the opposite direction, so that the AO guide star is picked up again. The loop then closes and exposure at the new position begins.
INGRID has a special observing mode especially for use with NAOMI, and is indicated in the row labelled "cds" in the Detector window for INGRID. This allows you to set up the number of exposures to add together (co-add) e.g. "rmode cds 1 60" sets it up to do 60 sec co-added exposures, reading into one frame, so that run 30 would now make 60 x 30 second exposures and co-add them into one frame. The idea of co-adding is to allow deep exposures without saturating bright objects.
with OASIS (in October 2001, pending NAOMI passing tests and schedule)
OASIS is an "integral field" spectrograph (e.g. like Sauron) that works best when the input image is less than about 0.35" wide. You then get sharp image data with spectral information at each pixel.
Set the pick-off X and Y positions to the center and acquire the target onto the WFS display as described above. When the star is centered, then move the telescope by about 1 arsec in the direction towards the science target, noting how much you have to move the pick-off to ce-center the star, and in which direction. You are now ready to make the full offset.
Following the offset, use MARK to store the current telescope position, then gocat to there. You are now ready to use the usual dither command.
In the future there will be a s/w procedure to do all this - promise!
LN2: INGRID needs to be filled in the middle of the night whenever NAOMI is on, because it's run without the cooler, to avoid vibrations.
Additionally, the WFS can be read out with 3 different binning arrangements: "full frame" (6x6), 4x4 and "quad-cell" (2x2), these numbers referring to the pixels assigned to each Hartmann spot. Increased binning allows you to increase signal-to-noise on fainter stars AND to read out faster (which should help with poorer seeing, but in NAOMI, has not yet been proved to do so...).
Each combination of lenslet array and binning is referred to (by NAOMI designers) as a "mode".
The most important ones are modes 1 and 2, while mode 8 was also tested (didn't work). Mode 1 corrresponds to ["good seeing" lenslets + full frame readout] and mode 2 is ["poor seeing" lenslets + full frame readout"]. Mode 8 is [4x4 lenslets + quad cell readout].
Transfer of TCS control to/from Naomi workstation ================================================== 1) Start TCS as normal 2) On navis authorize display from TCS Alpha xhost +lpas4 Then set up key definition (for <-INC). xmodmap -e "keysym F19 = Find" 3) From lpas4 create a second TCS information display USER> CLONE ON navis A slave copy of TCS information display should appear on navis in around 20 seconds. This display can be left running until TCS is shut down or can close later with CLONE OFF navis 4) Transfer control of TCS to navis USER> TRANSFER ON navis A terminal is created on Navis, with TCS user prompt. Takes about 20 seconds. In the TO's window a message says control has been transfered. 5) Transfer control back to TCS On navis : USER> TRANSFER OFF Control returns to TO window. There's no need to close the window on navis. This takes about 2 seconds. Subsequently control can be switched back and forth using steps 4 and 5. In emergency TO can grab back control by using control-Z 6) Use of TCS HANDSET from navis The key definitions on Navis are different TO key Navis key Function HANDSET COPY Enters/Exits HANDSET mode INC-> INSERT Select larger increments <-INC FIND Select smaller increments ALT/AZ none Not available RA/DEC F7 RA/DEC mode XY F8 X/Y mode OFFSET F9 Offset mode APOFF F10 Aperture offset mode FOCUS PROPS Adjust focus ROTATOR UNDO Adjust Rotator OWN None User entered increments not available Arrows Arrows Input increments (move by selected increment) Notes : i) In case names do not work, ip addresses can be used navis.ing.iac.es 220.127.116.11 lpas4.ing.iac.es 18.104.22.168 ii) Don't resize TCS USER window, as HANDSET display may not work correctly. Frank Gribbin 24-Aug-2000 Version 1