ATACAMA WORKSHOP, June 15-17 2000


Comparing DIMM Seeing To UT Image Quality	ATACAMA WORKSHOP, Ithaca NY M. Sarazin, June 15-17 2000, 7/14

Comparing DIMM Seeing To UT Image Quality

ATACAMA WORKSHOP, Ithaca NY

M. Sarazin, June 15-17 2000, 7/14

DIMM converts image motion into large telescope seeing with the assumption of an infinite outer scale of the turbulence. UT images turned out about 10% better than predicted by DIMM, confirming the finite character of the outer scale. Correcting for that effect is possible by removing from the DIMM the share of the tilt of an 8m aperture.

Comparison of DIMM seeing (Y axis) after correction for outer scale, with UT1 Science Verification (SV) Image Quality (X axis) as processed by the SV team from Test Camera long exposures, corrected for zenith and at 500nm.