Hyderabad: A month after a huge chunk of plaster fell from one of its minarets, a multi-censor scanning of the historical monument Charminar in Hyderabad was conducted on Friday. City-based startup Terra Drone India (TDI) undertook the multi-platform scanning of the monument, which was built as the city’s foundational building in 1591.
On 1 May, a huge chunk of lime-plaster from its south-west minaret broke and fell to the ground late in the night. Pictures from the site showed that the lime-plaster comprising eight flower-petals, sized about 2.5 metres/0.8 metres, came-off the minaret and fell to the ground. Since then, its custodian, the Archaeological Survey of India (ASI), had undertaken repairs.
As part of the repair work, TDI was invited by the Information Technology department of Telangana to provide innovative technological solutions for the digital preservation of Charminar. The startup used a handful of technologies to provide a holistic study of the monument’s structural integrity.
TDI used an ultrasonic pulse velocity testing, a non-destructive testing technique, to measure the air gaps that have developed in the areas of concern till date. It also undertook a high-accuracy visual which scan was carried out to maintain a record of the facade, actual color, and any visible cracks or crevices. Through this, a true color 3D model will be created.
A thermal scanning was also conducted to detect differences in temperature between different areas of the monument and identify how the different materials used in the monument are reacting to heat and how they are at risk of damage. And lastly, TDI also profiled and undertook a Lidar survey was carried out to create a high accuracy 3D model, accurate up to the millimetric level of the monument.
A press release from TDI said that the Lidar survey will help preserve the current existing infrastructural design and layout of the monument for future rebuilding or repair works.