Study Of Automatic Focusing Technique For Long Focus Oblique Real-Time Aerial Camera

Based on studying a long focus oblique real-time aerial camera, this paper studys the reason of being out of focus systematically, and points that the primary reason of being out of focus is due to the change of environment(temperature> atmospheric pressure) and oblique photographic distance, and according to the three factors ,talk about the effect on being out of focus of camera, the simple maths equation is presented in order to calculate out of focus. According to the optics system of oblique camera, make certain the scheme of auto-focusing system, and analyze its principle in detail. This paper presents a new method in order to compensate out of focus of oblique photographic distance, the principle is very simple and it is steady and reliable for structure design. A auto-focusing compensation machine is studied with double-deck guideway and double-deck cam, the double-deck machine's synchronous operation is able to compensate the deviation of focus, and ensure the opticus being fixed on the CCD's receiving surface during photography. On the basis of the precision analysis of focusing machine, we have tested the focusing principle of oblique photography, and do the experiment both on the ground and in the air. In the end, we draw the conclusion that the theory of the auto-focusing system is right and reasonable.