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Notes - Session 403 (2009-12-10)

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2009-09-19
Bullet Pec Refinement
 
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PEC Refinement

Two PEC refinements were performed during session S403, based on original PEC training run recorded during session S358 (2009-03-29)/refined during session S370 (2009-05-28)

Original Periodic Error Measurement (2009-03-29)
Original data showed periodic error of 32 arc sec (+/- 16 arc sec)
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Previous Refinement Run (2009-05-29)
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First Refinement 

Data acquired from 48 min run with PEC On (~2x24 min cycles), 
New data show significant residual periodic error of 20 arc sec (+/-10 arc sec)
suggesting that benefits for previous refinement in May 2009 have somehow been lost

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Image
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PEC Refinement
|
Red - previous PEC curve |  Blue - measured PE from first refinement run | Green - refined PEC curve  |
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Second Refinement 

Data acquired from second refinement run with PEC On (~1x24 min cycles), 
Traces show significantly lower residual periodic error

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Image 
 
PEC Refinement
|
Red - PEC curve after 1st refinement |  Blue - measured PE from second refinement run | Green - final new PEC curve (2) |
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Final Refined PEC curve (PemPro-2009-12-11-S403_RefinedPecCurve_2nd.ppc)
(uploaded to LX200R)

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Example of improvement in image quality from PEC refinement (part of NGC 2264 Mosaic)
Top image: a poor image affected by residual periodic error (not all frames are as badly affected)
Bottom image:  same area after PEC refinement

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CCD Image Montage
Top : 45s exposure, 3x3 binning, C Filter  2009-12-11 (#403357),
Bottom : 45s exposure, 3x3 binning, C Filter  2009-12-11 (#403365),


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Last Updated : 2015-05-16
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