What advanced sensing techniques are used to find lost treasures? Part 5: LiDAR

This series has previously addressed magnetometry, electromagnetic induction , ground penetrating radar and resistivity measurements. LiDAR (Light Detection and Ranging) is another sensing technique frequently used by archeologists and treasure hunters to find objects. While it can be used alone, it is often combined with electromagnetic induction, magnetometry and/or electrical resistivity measurements.

LiDAR data analysis has proven to be highly cost effective to verify the analysis from magnetometry surveys. Since it can be difficult to differentiate positive magnetic anomalies from former ditches from those caused by magnetically enhanced soil within earth banks, the magnetic data combined with LiDAR can help to confirm the nature of features located and indicate whether they still exist.

LiDAR technology uses time-of-flight (TOF) capability to measure the distance and reflectivity of objects. A complete LiDAR system, such as one from Quanergy, also records the data as a reproducible three-dimensional point cloud with intensity information. The laser operates at the 905 nm wavelength and can detect objects that vary in size, shape, and reflectivity and they are usually unaffected by ambient light/dark, infrared signature, and atmospheric conditions. See featured image on homepage (source: Quanergy.)

Solid state LiDAR systems such as Quanergy’s S3 and S3-Qi, contain no moving or vibrating parts on either macro or micro scales. The company’s advanced artificial-intelligence software enables the perception of objects based on data collected by one or more LiDAR sensors.

At archeology sites, LiDAR is typically used from planes or drones to support or enhance data from ground-level measurements. The 3D map generated from above can reveal geometric patterns, mounds, and indentations that cannot be detected from the ground.