NGAO LOWFS Object Selection Mechanism

Nomenclature:

NGAO LOWFS OSM

This is a interim OSM for the NGAO system, likely required for first light before the d-IFS is commissioned. The OSM contains:

• 2 TT star NIR WFS channels
• 1 TWFS NIR WFS channel
• 1 TTFA NIR WFS channel
• 1 wide-field PSF monitor
• 4 pick-off mechanisms to feed the star light to the respective WFS channel
• NB: the TWFS/TTFA WFS channels will be fed by 1 pick-off arm located on the brightest star in the field

Dec 14th, 2007

• Notes and Question on pupil to MEMS/lenslet registration in LOWFS channels
• Viswa's description of each NGAO WFS channel (TT, TWFS, TTFA, NGS HOWFS and LGS WFS)

Jan 16th, 2007

Update: the TTFA and TWFS WFS channels will be fed by 1 pick-off arm located on the brightest star in the LOWFS field of view. After chats with Viswa and Chris N, the original 4th pick-off arm should be used for a PSF monitor channel.

• Pick-off definition table for interim LOWFS unit and LGS unit

-- Anna Moore 12th Dec 2007