Abstract

Four generations of atmospheric isoplanatic angle sensors have recently evolved. An apodized 20-cm aperture lightweight low-cost instrument has been developed that achieves accurately weighted isoplanatic angle measurements with 1-s time resolution. Comparing data from four different locations in the northern hemisphere, at least three general isoplanatic angle categories are evident. Frequently we observe rapid, 10 s to several minutes, 200–400% variations in the atmospheric isoplanatic angle. The location of the atmospheric jet stream is the most significant forcing function.

© 1986 Optical Society of America