大气能见度是重要的气象参数之一，也是表征近地大气污染程度的一个重要物理量，精确能见度测量能提前避免飞机起落和汽车通行在低能见度状况下的事故隐患，在阴霾天气的监测中也发挥着很大的作用。现行测量能见度的专业仪器主要为透射式能见度仪和前向散射式能见度仪等，精度高且探测范围宽，但多为固定安装，限制了能见度测量的地域范围和灵活性。小巧灵便的普通数码相机弥补了这一缺点，在保证一定精度的前提下可以以较快速度移动测量，故可对突发情况或大范围内的能见度情况做出评定。此外，由于数码相机的高普及率，缺少专业仪器的气象爱好者也可使用这种方法对周围地区的能见度有进一步了解。

A new model is established to measure visibility by using digital cameras and improves the agility and the measuring range of Digital Photography Camera System for measuring visibility. The following work is done: 1) An object-observation point model, which is appropriate for using cameras to measure visibility, is built based on Koschmieder Formula and Lambert-Beer Law and it eliminates the physical quantities that cannot be measured by cameras accurately, such as the background diffused light, the sky background light in the direction of an object and the object reflex.2) The following Error analyses are done: The error caused by inadequate resolution of the camera lens, dark current, deviation of camera parameter’s (exposure time, aperture) actual value and show value and nonlinear photoelectric response is diminished by finding the relationship between grayscale per pixel and luminance and some factors such as the properties of the object surface, the intervals of object and observation point are restricted. 3) A certain number of visibility records are obtained by utilizing, the model established above .Correlation coefficient is 99% the accuracy’s 17%. The result proves the feasibility of using camera to measure visibility preliminary.