ILLUMINANCE MAPPING OF NIGHTTIME ROAD ENVIRONMENT USING UNMANNED AERIAL SYSTEM
One purpose of road lighting in night-time environment is to allow pedestrians safe passage and provide sense of security. To attain this purpose, guidelines are set to make sure that proper lighting are present in roads. Current mapping of road lighting in the Philippines is a tedious process. To address this issue, an alternative method of mapping illuminance using Unmanned Aerial System is developed. A 3D model of the road was created using overlapping images and is the basis of the data points. The results of the calibration show that each of the camera channels, as well the photopic luminance value denoted as ND, shows a linear trend with the illuminance value recorded within the subject area having a range of 0.17 to 15 lux. Linear regression models using each of the channels of the camera and ND can be used to calculate illuminance with RMSE of less than 0.6 lux. It also shows that all values calculated from all regression models exhibits similar trend with blue differing by being generally lower in value. With blue as the best linear regression model, 3D and 2D models of illuminance were created. With these results, it can be concluded that application of photogrammetry through UAV-mounted camera can be used to map illuminance at low level lighting.