Tests of AST3-2 at Xinglong: Image Analysis Ma Bin NAOC

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 sec, 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 !