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 !