Script for AGw Spiral Search to Find Unknown Guiding Hotspot

Overview

This wiki page is the starting point for a suggestion from SWG to make a script that automates a spiral search procedure to move the off-axis AGw probe and then take guider and wfs images to identify the location of the guiding hotspot.

The initial application is for alignment in the lab, but such a script may have some use on-sky as well.

The first crude version of the script created on 20200820 is /lbt/lbto/supportscripts/ObserverSupport/agw_spiral.py with MANY things hardwired. A companion script to take a focus sequence is: /lbt/lbto/supportscripts/ObserverSupport/agw_focus.py

Basic Functions

  • Check TCS authorization for the specified AGw unit
    • Could be hardwired or a config parameter for now.
  • The script will move the AGw off-axis probe.
    • move according to a spiral pattern with specified starting position and pitch
    • check next position for being within simplified AGw limits of travel
    • Use the oacontrol setxy command
    • setxy -u 1 -x 3.4 -y 617.0 on the oac machine, where -u specifies the AGw unit number, -x and -y specify the probe coordinates in mm

  • At each position, the script will take guider and AGw images serially.
    • Use the gcsclient readWFSCam and readGuideCam commands.
    • gcsclient readGuideCam left -e 1000 where 1000 is the exposure time in millisec
    • gcsclient readWFSCam left -e 10000 where 10000 is the exposure time in millisec
  • The script will report time, X-Y position, and image names (with corrected paths).

Configuration Parameters

  • AGW number
  • Authorized Instrument / Focal Station (fcn of AGW number)
  • X,Y starting position (mm)
  • Spiral Pitch (mm)
  • Guider Exposure Time (millisec)
  • WFS Exposure Time (millisec)
  • Number of half-spiral loops (a stopping parameter)

Advanced Functions to be Added Later

  • Measure centroid of star in GuideCam image.
  • Recognize with the WFSCam image is illuminated through the pinhole.
  • Optimize spiral pattern to measure a precise (sub-pixel) hotpsot

  • A script to do automated display of the latest images
    • After the model of RB_Science (which has stability issues)
    • Or after the model of LBTdisp (which hasn't been tested much)

Sample Output

The first version of the agw_spiral.py script produces output like this:
./agw_spiral.py script version of 20-Aug-2020 at  03:30:22  UT

Spiral pitch is  0.6  mm, with  10  semi-loops
1 1 0 4.5 612.6
ssh oac@oac 'setxy -u 1 -x 4.5 -y 612.6'
gcsclient readGuideCam left -e 100
03:30:23 4.5 612.6 /lbt/data/share/tcs/telescope.20200821/left_guider000001.fits
gcsclient readWFSCam left -e 5000
03:30:26 4.5 612.6 /lbt/data/share/tcs/telescope.20200821/left_wfsc000001.fits

1 1 0 5.1 612.6
ssh oac@oac 'setxy -u 1 -x 5.1 -y 612.6'
gcsclient readGuideCam left -e 100
03:30:35 5.1 612.6 /lbt/data/share/tcs/telescope.20200821/left_guider000002.fits
gcsclient readWFSCam left -e 5000
03:30:38 5.1 612.6 /lbt/data/share/tcs/telescope.20200821/left_wfsc000002.fits

2 -1 0 5.1 612.0
ssh oac@oac 'setxy -u 1 -x 5.1 -y 612.0'
gcsclient readGuideCam left -e 100
03:30:48 5.1 612.0 /lbt/data/share/tcs/telescope.20200821/left_guider000003.fits
gcsclient readWFSCam left -e 5000
03:30:50 5.1 612.0 /lbt/data/share/tcs/telescope.20200821/left_wfsc000003.fits

-- JohnHill - 20 Aug 2020
Topic revision: r4 - 25 Aug 2020, JohnHill
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