Comparisons on Calculating Methods of Total Daily Global Solar Radiation in Urban Area Based on Panoramic Images

In this paper, the total daily global solar radiation is tested at 18 locations with different morphological characteristics in Xi’an University of Architecture and Technology. PTgui is used to convert the panoramic pictures from Baidu Street Map to fisheye images. Sky view factor (SVF) and tree view factor (TVF) are calculated by Rayman model with fisheye images. SVF is used to calculate the total daily global solar radiation at the 18 locations with two different methods and TVF is used to classify the locations. The calculations and testing results are compared and combined the morphological characteristics. Then it is found that using suitable methods on different locations is necessary to obtain more accurate results whether the TVF (tree view factor) is more than 0.3 or less. To obtain solar radiation at different locations in the urban area, the calculating methods should be carefully chosen based on the morphology characteristics of the location.