Large-Scale Modeling of Urban Rooftop Solar Energy Potential Using UAS-Based Digital Photogrammetry and GIS Spatial Analysis: A Case Study of Sofia City, Bulgaria. - Dimitrov, Stelian; Iliev, Martin; Borisova, Bilyana; Petrov, Stefan; Ihtimanski, Ivo; Todorov, Leonid; Ivanov, Ivan; Valchev, Stoyan; Georgiev, Kristian (Urban Science, 2026)