Role of the inner scale of atmospheric turbulence in optical propagation and methods to measure it

This is an invited tutorial paper, including relevant results of our research. After a short description of the atmospheric turbulence and its models, the effect of the inner scale on laser scintillation is described and methods to measure the inner scale based on laser irradiance are mentioned. Then the effect of the inner scale on phase related quantities is investigated, namely: (differential) angle of arrival on a beam front, and wandering of thin beams. Several methods, developed by us, are described to measure the inner scale by using phase dependente quantities.