David's Astronomy - Notes 2009-09-19 (S00389)

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)

Previous Refinement Run (2009-05-29)

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

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

Second Refinement

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

PEC Refinement
| Red - PEC curve after 1st refinement | Blue - measured PE from second refinement run | Green - final new PEC curve (2) |

Final Refined PEC curve (PemPro-2009-12-11-S403_RefinedPecCurve_2nd.ppc)
(uploaded to LX200R)

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

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),

This Web Page:	Notes - Session 403 (2009-12-10)
Last Updated :	2015-05-16

	2009-09-19
	Pec Refinement

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David's Astronomy Pages Notes - Session 403 (2009-12-10)

PEC Refinement

David's Astronomy Pages
Notes - Session 403 (2009-12-10)