Tests of AST3-2 at Xinglong: Image Analysis Ma Bin NAOC 2013.05.20 Tests of AST3-2 at Xinglong Date: late Feb – early April Tests: focusing pointing, tracking operation & data system auto-survey real-time pipeline & database remote 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 transfer 0.43sec 2640 lines bright star -> trail high speed sampling Trail of Bright Star Movement of the center when both tracking and untracking Cause: Seeing？ Shake of the telescope？ Thank you !