Very large telescope projects, due to their increased expected performances and cost, have prompted several campaigns to compare existing and potential observatory sites throughout the world.ln the frame of the ESO-VLT studies, an extensive geographical survey of Northern Chile led to the selection of a few representative summits for comparison with the observatory of La Silla. Standard meteorological towers, acoustic radar, Rawinsondes, microthermal sensors and optical seeing monitors will be collecting experimental data in the years to come. After a brief review of the relations between atmospheric and optical seeing parameters, the particular case of Northern Chile is described with the help of data collected up to naw..Then follows a technical description of the instrumentation developed by ESO including the differential Hartmann open air monitor.
Marc S. Sarazin,
"Eso-Vlt Instrumentation For Site Evluation In Northern Chile", Proc. SPIE 0628, Advanced Technology Optical Telescopes III, (20 August 1986); doi: 10.1117/12.963520; https://doi.org/10.1117/12.963520