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SHARCS Problem: Artefacts In Dither Positions
Manifestation:
Strange artefacts at certain NGS dither positions (i.e. horizontal stripes
in vicinty of object, and reduced flux in object) accompanied by partial
waffle pattern on tweeter.
Noticeable at NE and SW dither positions when using script:
/local/u/user/observers/lgs/scripts/saoBxy4NGS
when using a dither scale of 3 arcsec.
Similarly, noticeable at SW dither position when using script:
/local/u/user/observers/lgs/scripts/saoBxy4NGS
when using a dither scale of 2 arcsec.
Workaround:
Cause:
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WFS steer 1Rx (or other) motor fails to calibrate, forcing a
workaround.
Hence the affected mirror is probably in the slightly the wrong place
for field steering.
If the affected stage can be calibrated, it should fix itself.
Associated Issues:
Change Log:
- 2017-05-10: First version.
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