公安专用视频监控系统前端覆盖影响因素

Influencing Factors for Front-end Coverage of Public Security Video Surveillance System

对于公安专用视频监控系统而言,前端摄像机传感覆盖区域模型的确立对于指导前端布点工作和辅助业务应用有着重要的作用。据此从公安专用视频监控系统的前端实际部署环境出发,推导出前端摄像机实际的地面覆盖模型;并推导出该覆盖模型的几何特征以及数学表达式。在此基础上得到了影响前端覆盖模型的影响因素分别是:(1)架杆高度;(2)安装俯角;(3)前端镜头焦距;(4)感光元件芯片尺寸。通过上述方法可以预测这些因素的变化作用下覆盖模型的几何特征变化趋势;再通过对摄像机样品的前端覆盖范围进行实验测试;并将实测值与计算预测值对比,验证了方法的可行性与合理性。

For the public security video surveillance system,the establishment of the front-end camera sensing coverage model plays an important role in guiding the work of front-end distribution and improving business applications.With reference to the actual deployment environment of public security video surveillance system,front-end camera coverage model on the ground is derived,and furthermore the geometric features and mathematical expression of the covering model are also deduced.The work above shows that the influencing factors of the front-end coverage model are these①front-end height;②installation angle③the focal length of lens;④chip size of photosensitive element.The variation trend of geometric features of coverage model can be calculated by the method proposed above based on these factors,at the same time the measure tests for the coverage model shifting of sample camera are carried on,the comparisons of values measured with the values calculated demonstrate that the proposed method is feasible and reasonable.