Validation of Sunlight Simulation Using Feature Extraction from Observed Image Data

In this study, we validated a 3-dimensional sunlight simulation model using GIS data and planetary position calculations, using numerical data derived from feature extraction of observed images. Observations were extended for ±3 days around the spring equinox, summer solstice, autumn equinox, and winter solstice of 2023 to exclude periods of blocked sunlight due to clouds or fog. The simulation, applied to an apartment complex, evaluated the sunshine matching rate (SMR) using the Kronecker delta function(δ). GIS modifications (GISm) improved shadow prediction accuracy by 0.57% to 15.56% compared to the original GIS data (GISo), with an average SMR accuracy 9.84% higher. This study confirms that detailed GIS spatial data significantly enhances simulation accuracy, and increasing GIS data resolution is expected to improve results further. It is also suggested that these models should be compared with commercial software and continuing applied research to provide reliable foundational data for legal disputes and environmental impact assessments.