ATACAMA WORKSHOP, June 15-17 2000


Comparing DIMM Seeing to Large Telescope Image Quality	ATACAMA WORKSHOP, Ithaca NY M. Sarazin, June 15-17 2000, 8/14

Comparing DIMM Seeing to Large Telescope Image Quality

ATACAMA WORKSHOP, Ithaca NY

M. Sarazin, June 15-17 2000, 8/14

DIMM converts image motion into large telescope seeing with the assumption of an infinite outer scale of the turbulence. Assuming that the outer scale larger than the telescope aperture, a first order correction is obtained by removing the one axis image jitter (Gradient tilt) variance from the long exposure FWHM:

Outer scale correction coefficient to apply to the DIMM estimates of the image quality of a 8m telescope limited by the atmosphere, for 0 and 60 degree zenith angle, as a function of the observing wavelength (the following central wavelength of the bands [U, B, V, R, I, J, H, K, L, M, N] have been respectively used in micrometers: [0.36, 0.44, 0.55, 0.64, 0.79, 1.25, 1.65, 2.2, 3.4, 5.0, 10]).