The role of the atmosphere in target acquisition modeling is investigated experimentally. Three models are compared to experimental results measured on the Golan Heights, israel. Concepts considered are atmospheric attenuation versus atmospheric blur, and contrast- limited (blur-limited) versus noise-limited imaging. Results indicate that the role of the atmosphere in target acquisition is blur rather than attenuation and that for ranges of the order of a few kilometers, modern sensors are limited by atmospheric blur rather than by noise. A significant portion of the atmospheric blur derives from small angle forward scattering by aerosols, which actually increases measured temperature differences for ranges up to a few kilometers.