Methods and systems are described for a system for measuring aberrations in a wave front. In the improved system multiple closely-spaced, small-aperture laser beams traverse an aberrating flow that introduces deflections of small-aperture laser beams from which aberrated wavefronts can be constructed. These beams may then be focused on position sensing devices using focusing lenses. The position sensing devices may then detect the positions of these beams and a difference between the detected position and the unaberrated position of the beams detected. This information may then be used to determine information regarding the optical aberrations introduced by the flow that may be used, for example, in improving communications systems and/or laser weapon systems.