航空相机焦距CCD精密测量系统

Precision measuring system of focus to aerial cameras with CCD

针对传统焦距测量方法误差较大(0 24%)的问题,提出了一种测量航空大孔径相机焦距系统,论述了系统的测试原理和组成。该系统采用长焦距平行光管和面阵CCD(ChargeCoupledDevices)摄像头接收图像,利用动态扫描和灰度质心法,有效地测量最佳图像位置和尺寸,使CCD上的图像分辨率达到光敏元尺寸的1/10,焦距的测量精度达到了0 1%,从根本上克服了传统测量方法的误差。与传统方法相比,实现了航空相机镜头焦距的实时在线精确测量和实际成像面位置是否正确的精确判断。

In view of bigger error(0 24%)of conventional measuring method,this paper focuses on a bigger aperture aerial camera focus measuring system and discusses measuring principle and structure of the system. The image in this system is received by the collimator of long focus and area CCD(Charge Coupled Devices) camera. Using dynamic scanning and center of gravity method,the system measures effectively the location and size of the optimum image. The image resolution of CCD can be up to one tenth of the size of the photosensitive sensor and the precision of 0 1 percent of focus measuring can be obtaind. The problem of the larger error of conventional measuring method is salved fundamentally. The accurate,real-time and on-line measurement of the focus of aerial camera lens can be realized and the exact determination of the position of the surface can be determined.