1. College of Civil Engineering, Anhui Jianzhu University, Hefei 230601, China
2. Institute of Urban Construction, Anhui Xinhua College, Hefei 230088, China
3. 2nd Construction Co., Ltd. of China Construction 5th Engineering Bureau, Hefei 230051, China
4. Ningbo Institute of Surveying, Mapping and Remote Sensing, Ningbo 315042, China