Optical refraction angle variations and multipath propagation from space observations

The photos of the setting Moon taken from space with angular resolution about 10 arcsec were processed. The small-scale variations of arrival angles were measured from the shape of the Moon's contours distorted by refraction. Along with noticeable variations of refraction angles the numerous cases of multipath propagation were observed. As a result statistical characteristics of refraction angle variations and multipath propagation were estimated for the height interval 10 to 30 km. The RMS value of relative variations of refraction angles with the scales less than 1 km was about 0.017. The probability of multipath propagation during observations from the height 350 km was estimated about 10%, and the maximum observed spread in arrival angles during multipath propagation was 80 arcsec.