Low cost digital photography approach to monitoring optical bending and guiding in the atmosphere

A low-cost system consisting of a commercial DSLR camera and a long focal length zoom lens is introduced for the purpose of recording the guiding and bending phenomena caused by atmospheric refraction in the planetary boundary layer. A significant advantage of this system is that long duration monitoring (weeks or months) is possible with the camera operated in a time-lapse mode. Recent experiments were performed with this type of system over a 12.8 km path in Dayton, OH and a 15.3 km path in Las Cruces, NM. The measured downward vertical drift of the target images in daytime (10 to 50 pixels) are roughly consistent with an approximate theory outlined in this paper.