Archaeologists using LIDAR Technology amidst Lockdown

Context: Recently, a U.K.-based team of archeologists has continued its research over the Tamar Valley through LiDAR (Light Detection and Ranging) despite lockdown due to Covid-19 in the country.
About the study

• The research team is currently studying the Tamar Valley, a rich archaeological landscape with many sites belonging to the Iron Age and Roman era with a future plan to study other areas like Bodmin Moor and Dartmoor, Plymouth and Barnstaple covering 4,000 sq. km. approximately.
• They have also located around 20 prehistoric burial mounds, remains of hundreds of medieval farms, and a few quarries.
• The images are taken during aerial surveys and then the vegetation and buildings are removed from the map to take a closer look at the land surfaces for the study and further analysis. 

LiDAR for India

• Though LiDAR has been used for agriculture and geology-related applications, India has still not used it in archaeology. This technology had immense potential for India.
• Remote sensing techniques such as LiDAR would be time saving and most useful in detailed study even if the concerned sites were under dense vegetation.

About LiDAR

• LiDAR stands for light detection and ranging and is basically a remote sensing method that uses light in the form of a pulsed laser to measure distances to the subject. 
• The light pulses along with other data generate accurate, high-resolution three-dimensional information of the object.
• There are two types of LiDAR namely topographic and bathymetric. Topographic LiDAR typically uses a near-infrared laser to map the land, while bathymetric lidar uses water-penetrating green light to also measure seafloor and riverbed elevations.
• LiDAR, is a remote sensing method that uses light in the form of a pulsed laser to measure ranges (variable distances) to the Earth.
• LiDAR uses ultraviolet, visible, or near infrared light to image objects. It can target a wide range of materials, including non-metallic objects, rocks, rain, chemical compounds, aerosols, clouds and even single molecules.
• This technology is commonly used by geologists and surveyors to make high-resolution maps, laser light is used to survey a site and its reflection is measured with a sensor.

Disadvantage of LiDAR

• It can’t perform well in fog, rain, snow and dusty weather.
• Need secondary cameras: LiDAR also struggles to detect a glass wall or door, which is why smartphone manufacturers and self-driving cars makers use LiDAR along with secondary cameras and sensors.