Digital Documentation of Saudi Built Heritage: Al-Arfa' Castle

Abstract. This study presents a comprehensive approach to the 3D documentation of Al-Arfa' Castle in Taif, Saudi Arabia, utilizing advanced digital documentation techniques. The project aimed to create a high-resolution 3D model to support conservation and restoration efforts. The methodology integrates terrestrial laser scanning (TLS), close-range photogrammetry (CRP), and LiDAR scanning. The study highlights challenges such as restricted drone access and environmental constraints, which impacted data acquisition. The integration of TLS and photogrammetry provided a highly detailed and accurate representation of the castle, demonstrating the importance of multi-source data fusion in heritage preservation. This paper evaluates three core questions: (a) How does CRP alone compare to TLS in terms of geometric accuracy? (b) What are the strengths and limitations of iPhone 15 Pro Max LiDAR for heritage documentation? (c) Does a fused multi‐sensor model outperform each single‐sensor dataset on accuracy, completeness, and efficiency metrics. The findings contribute to advancing digital heritage documentation by showcasing an optimized workflow for combining TLS, CRP, and LiDAR data, ensuring precise and scalable documentation for future conservation efforts.