Science

For useful shortcuts: Making offsets using Markers on the cameras

For most recent positions: Current best position for markers (CWFS,IHMP, etc.)

Setup

1) The RA (or OCD/HObs) loads the trajectory and sets the probe positions (using the output of shuffle), issues the go_next command, and informs the TO of the setupmethod for this target. The target_setup "-to" option should copy the current fake-ACAM image to: nossy/noss/htopx2/acam.html . There are also commands on the RA-side to set the catalog magnitudes of the guide stars in PAS for accurate transparency measurements.

2) The TO runs the appropriate script for this setup, using button in OTT interface. Each instrument/setup is a little bit different, but there are some guiding principles:

• The TO is generally responsible for the Guiders, Wavefront Sensors, Tip/Tilt Camera, ACQ camera, HPF ACQ camera, focus, etc.
• OTT and the TO setup scripts will control the GC/ACQ filters, WFS/GC/ACQ/HPFACQ exposure times, analysis regions, fiducials, always storing images, etc
• When TO clicks "setup complete", the telescope should be fully ready for the science observation to begin. This means the ACQ mirror should be retracted, pipeline stopped, and everything ready for the science exposure to start. The wavefront sensor may be activated shortly afterward to provide fine focus corrections, but the telescope should already be in rough focus (<0.1mm).
• RA "iexp" script will wait for "setup complete" and then start exposing with the science instruments (possibly verifying that ACQ mirror, FCU head, etc are retracted)
• At end of science exposures, RA script will flag setup as "false", which is the cue that we can move on.
• At end of HPF exposures, post-observing ACQ image will be taken with a method yet-to-be-determined (right now with "iexp" script)

What follows are ideas of how these /should/ work, not necessarily how they *do* work. This is a work in progress. -- March 2021, SJ

Commands from RA side to set up on target:

• Copy fake-ACAM image to nossy/noss/htopx2/acam.html, update setup method, etc
• If on a trajectory, cancel_trajectory()
• Load_trajectory() for this target
• Set all probe positions for "next" (can this be done while trajectory is being canceled?)
  • tcs.Guider1_set_position()
  • tcs.Guider2_set_position()
  • tcs.WFS1_set_position()
  • tcs.WFS2_set_position()
• tcs.go_next()
  • waits for that to return before continuing...
• set magnitudes/IDs for probe stars:
  • pas.Guider1_SetObjectAndMagnitudes()
  • pas.Guider2_SetObjectAndMagnitudes()
  • pas.WFS1_SetObjectAndMagnitudes()
  • pas.WFS2_SetObjectAndMagnitudes()
  • if directACAM setup, send target magnitude to PAS for ACQ
• tcs.set_metadata() for the target using queue data/etc
• play "ready for setup" sound
• tcs.wait_for_setup()

• somewhere in here, probably before the go_next() command, the RA scripts need to:
  • start extra pre-calibrations if requested (e.g., LFC)
  • set UTDATE of observation
  • attach to one/both instruments (if parallel)
  • get observation number from DB

Commands from RA side after setup_complete:

• VIRUS and LRS2:
  • virus.enable_shutter() or lrs2.enable_shutter()
  • tcs_proxy.pfip.AdjustDither(pos=1)
  • For every exposure
    • Signal message start to message board
    • pfip.AdjustDither()
    • if parallel, start appropriate exposure
    • virus.expose() or lrs2.expose()
    • virus.wait_for_shutter_close()
    • If dithering:
      • tcs.Guider1_offset_fiducial()
      • tcs.Guider2_offset_fiducial()
    • virus.wait_for_readout() (except not on last exposure)
    • check for user abort request
  • tcs.update_setup(state=false)
    • "exposure finished" sound
    • can cancel trajectory and go to next target
    • may need to start post-exposure calibration (e.g., LFC)
  • clear metadata

• HPF:
  • PFIP shutter is already open for HPFACAM setups, so go straight to:
    • ssh command to start exposure on hpf system
    • start parallel VIRUS exposure
  • PFIP shutter is closed(?) for DirectACAM setups, so:
    • open PFIP shutter?
    • ssh command to start exposure on hpf system
    • start parallel VIRUS exposure
  • after HPF exposure finishes:
    • If HPFACAM setup: deploy ACQ camera mirror, set short exposure time, take 1 image, indicate OBJECT keyword or something to tell what it is
      • should this be done by TO script?
    • close PFIP shutter
    • "exposure finished" sound
    • can now cancel trajectory and go on to next target
    • may need to start post-exposure calibration (e.g., LFC)
    • clear metadata

Setup procedures on the TO side (mostly via OTT and setup scripts)

• TO uses OTT to click setup/instrument of choice (or maybe this is automated?)
• OTT deploys ACQ camera mirror
• OTT sets guider/ACQ filters to:
  • g` for LRS2-B and VIRUS
  • r` for LRS2-R
  • i` for HPF
• OTT sets guider exposure times to 6s (or not?)
• OTT sets WFS exposure times to 5s
• OTT sets analysis region and fiducial on ACQ camera based on best marker position, using IFU in setup?
  • 000 --> IHMP position
  • 056 --> LRS2-B position
  • 066 --> LRS2-R position
  • 600 --> HPFACAM position ("regular")
  • 603 --> HPF science fiber position ("direct")
  • 555 --> BIB position
• OTT starts ACQ camera pipeline and metrology loop (saving images)
• OTT starts Guider/WFS camera pipelines and metrology loops (saving images)
• OTT sets analysis regions and fiducials on Guiders based on best marker positions
• OTT tunes PID loops on guiders/ACAM/HPFACAM

Once the trajectory has started and the "correct for structure" has completed:

• TO offsets target to desired position (directACAM), or offsets nearby star to position from finder chart (ACAMblind), or centers a guide star and activates it (directGuider), or offsets target to HPFACAM position (HPFACAM) ---- all of these are done as a "pointing correction" so we know the offset.
• If directACAM or ACAMblind:
  • TO activates metrology loop (guiding) on the ACQ camera
  • TO offsets both of the guide probes to center the guide star in the field; focuses within 0.1mm of best focus
  • if the star on the ACQ camera is positioned and steady at the correct pixel coordinates then make and set a guide box on the guide probe and hit start loop. After the image refreshes you will see a red cross mark on the guide cam, that is your new fiducial. At this point you can deactivate loop and stop loop on the ACQ and start loop and activate loop on the guide probe.
  • TO retracts ACQ mirror and stops ACQ pipeline (making sure at least 1 ACQ image is stored while guiding on the guider - TBD: identify/flag the final "setup" image - maybe header keywords or metadata with PROGID and QIDX?)
• If HPFACAM:
  • These will have happened earlier:
    • OTT opens PFIP shutter
    • OTT sets exposure time on HPFACQ camera to 9s
    • OTT sets analysis region and fiducial on HPF ACQ camera
    • OTT starts HPF ACQ camera pipeline and metrology loop (saving images)
  • After TO coarsely centers the star on HPF Regular fiducial on ACQ camera, OTT retracts ACQ camera mirror, stops ACQ camera pipeline, activates metrology loop on HPF ACQ camera
  • OTT prompts TO for guider number to set up on
  • OTT sets analysis region and fiducial on selected guider
  • OTT prompts TO to center star in guider, then press "enter"
  • OTT offsets by dx,dy=+5,+4 arcsec (or whatever current values are in use)
  • OTT prompts TO to handshake from HPF ACQ camera to selected guider then press "enter"
  • OTT offsets guider by final dx,dy values
  • OTT stops HPF ACQ camera pipeline
• TO clicks "Setup Complete" and tell the RA that the telescope is ready
• RA script starts science exposures; RA monitors sky quality and science data quality
• TO centers and activate a wave-front sensor (this can be started earlier in the process as well)
• TO monitors metrology from guiders, wavefront sensors, and tip-tilt camera during science observation
• At the end of the HPFACAM setup, SOMEONE inserts ACQ camera mirror and takes 1 image (by cycling the pipeline) before canceling the trajectory and setup (TBD: identify/flag the post-observing image - maybe set header keyword?)
• After that, RA script knows when it is time to flag setup as false, cancel the trajectory, and send the next target

Blind offsets from ACAM without using HPFACQ in the HR mode

Run shuffle with the fiber ID of 603 instead of 600. Use the HPF_HRfiber position to setup on in the ACAM. If there is uncertainty about the position then measure it at the end of a regular HPF setup to confirm the position. Do the handshake from the ACAM to the best guider choice. pull out the ACAM and start the science exposure.

HPF regular setup offsets:

• syscmd -T 'Guider1_offset_probe (dx_ang=5,dy_ang=4)'
• syscmd -T 'Guider1_offset_fiducial (dx_asec=-9.6,dy_asec=-5.5,compensate="true")'

OR

• syscmd -T 'Guider2_offset_probe (dx_ang=5,dy_ang=4)'
• syscmd -T 'Guider2_offset_fiducial (dx_asec=-9.6,dy_asec=-5.5,compensate="true")'