Rescue Documentation and Digital Preservation of Alambagh Palace: A Comparative TLS-Based Heritage Survey in Uttar Pradesh

The rapid deterioration of historical monuments in India necessitates the adoption of advanced digital documentation methods for heritage preservation. This study presents a detailed Terrestrial Laser Scanning (TLS) survey of the Alambagh Palace in Lucknow, a Nawabi-era structure built by Wajid Ali Shah and currently in a state of neglect. Using the Leica ScanStation P40 and Differential GPS for global referencing, high-density point clouds were generated to achieve millimetric precision in documenting architectural features, including missing turrets, eroded floral motifs, and structural cracks. Photorealistic 3D models were developed to support conservation planning, immersive visualization, and virtual heritage tourism. Comparative analysis with other TLS-based surveys in Uttar Pradesh—such as Gulistan-e-Iram, Farhat Baksh Kothi, Chhatar Manzil, Kardameshwara Mahadev Temple, and Shri Kashi Vishwanath Temple—highlights both methodological consistency and site-specific challenges. Unlike policy-driven projects such as Kashi Vishwanath, the Alambagh survey exemplifies preventive digital preservation, emphasizing the urgent need for a state-level digital heritage repository. The findings demonstrate the scalability of TLS technology across secular and sacred contexts, offering new opportunities for conservation science, heritage policy, and digital tourism in India.