Visit to Lick Observatory (LGS run)

July 15-16, 2013

The telescope:

  • 3-m Shane telescope.
  • Equatorial mount.
  • Built in 1950.

WP_001421.jpg WP_001425.jpg

The laser:

  • Sodium laser
  • ~10W
  • Off-axis (south)
  • 4x flash-pumped solid-state Nd:YAG lasers (1024 doubling to 532) pumping a dye laser

Inside the laser room. From left to right: Kostas Chloros (Telescope Ops Mgr), the dye laser cabinet (containing the dye pumps), the dye laser unit and the four solid-state lasers.

Aircraft spotters:

  • 2 spotters outside in "spotter booths".
  • 7 hour shifts with one 15-min paid break, no backups.
  • Both radio and kill switch are wired, as it was required by FAA back then.
  • Clear-Com radio units (wired)
  • Laser operator wears handset.

Spotter Booth


  • Laser Operator GUI has a diagram of the laser system with clickable areas.
  • Audible signals for events.
  • Radar for automatic aircraft detection (Bendix). It was installed early on. Used as an emergency shutdown backup. Mounted on the top ring, next to the launch telescope output.
  • Two shutters: one "fast shutter" (inside laser box) for emergency shutdowns and one "exit shutter" (at the top of the launch telescope) for normal operation.
  • For focusing the laser spot on the sodium layer, the laser is projected on top of a 9th-mag natural star, to use it as a reference of best focus.

Laser Operator GUI

Space Command Interface:

  • PRM files are created from a list of targets provided by the observer. The list includes a name and the coordinates
  • PAM files are parsed to create independent files per target (associated with the name provided by the observer).
  • There is no telescope position feedback, so no automatic target pointing verification, only automatic time closures ("Laser Shutdown Monitor")
  • The GUI indicates time remaining, length of upcoming closure and a list of next windows (with duration and length of following closure).
  • A yellow indicator occurs at the 2-min before closure mark, orange at the 1-min mark, and red during closure. Shutdown occurs at T-1 sec (safety buffer to account for any delays).

Space Command GUI

-- GustavoRahmer - 20 Jul 2013
I Attachment Action Size Date Who Comment
WP_001404.jpgjpg WP_001404.jpg manage 127 K 25 Jul 2013 - 22:54 GustavoRahmer  
WP_001410x.jpgjpg WP_001410x.jpg manage 85 K 20 Jul 2013 - 00:14 GustavoRahmer Space Command GUI
WP_001418.jpgjpg WP_001418.jpg manage 90 K 25 Jul 2013 - 22:13 GustavoRahmer  
WP_001419.jpgjpg WP_001419.jpg manage 88 K 25 Jul 2013 - 22:18 GustavoRahmer  
WP_001421.jpgjpg WP_001421.jpg manage 110 K 25 Jul 2013 - 22:24 GustavoRahmer  
WP_001423.jpgjpg WP_001423.jpg manage 117 K 25 Jul 2013 - 22:33 GustavoRahmer  
WP_001423x.jpgjpg WP_001423x.jpg manage 110 K 20 Jul 2013 - 00:15 GustavoRahmer Laser Operator GUI
WP_001425.jpgjpg WP_001425.jpg manage 118 K 25 Jul 2013 - 22:24 GustavoRahmer  
Topic revision: r4 - 18 Sep 2014, GustavoRahmer
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