Aero-optical effects, part II. Sources of aberrations: tutorial

This paper serves as Part II of a two-part tutorial on ``aero-optical effects.'' In Part I, we provide introductory material with an emphasis on system-level considerations, particularly for those who are new to the field of aero-optics. In Part II, we move on to survey several sources of aberrations. For example, we cover foundational sources like boundary layers and shear layers, as well as miscellaneous sources like mechanical contamination, shock waves, and aero acoustics. Throughout Part II, we emphasize drivers for system-level performance, which appropriately builds on the system-level considerations covered in Part I. This emphasis will inform future efforts looking to develop airborne-laser systems flying at subsonic, supersonic, and hypersonic speeds.