Tests of AST3-2 at Xinglong: Image Analysis
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Transcript of Tests of AST3-2 at Xinglong: Image Analysis
Tests of AST3-2 at Xinglong:Image Analysis
Ma BinNAOC
2013.05.20
Tests of AST3-2 at Xinglong
Date: late Feb – early April
Tests:focusingpointing, trackingoperation & data systemauto-surveyreal-time pipeline & databaseremote control
High Dark Level
CCD TEC did NOT work well t_CCD ~ t_air ( ~ 0℃) dark: 100ADU/s (sky: 10ADU/s) Pixel-to-pixel variance Limiting depth!
Field Rotation
Alt-Az mount
Field Rotation
30 sec
Field Rotation Speed
Limiting Exptime !
Focusing
Steps:
• Frames at diff. f
• FWHM measurement
• Fitting
Influences:
• Seeing
• Unsteady due to movement
Focal Plane
Pointing Correction
Tpoint:telescope axes .vs.alt-az
Pointing Time
Neighbor field: 1.5 degree
Firstly criterion RMS<2“, 40sec
0324 20sec, but elongated
0409 RMS<1.5”, <15sec, unelongated
Astrometric Accuracy
0324 M35 1ses
Scamp Ref cat: PPMX
RMS ~ 0.15”
Limiting Mag
0306 open cluster M44 10sec
Trail of Bright Star
Frame transfer0.43sec 2640 linesbright star -> trailhigh speed sampling
Trail of Bright Star
Movement of the center when both tracking and untracking
Cause:Seeing?Shake of the telescope?
Thank you !