Digging with light: Airborne multispectral imaging
At the 2025 ArcheoScienceFest in Castellum, Utrecht, we took part in a lively science dialogue session titled Airborne Multispectral Imaging, led by Matthias Lang and Wouter Emaus. The event combined Roman ruins with remote sensing — and offered a glimpse into how drones, wavelengths, and algorithms are quietly revolutionising archaeological discovery. What is airborne multispectral imaging? Multispectral imaging (MSI) involves capturing data across several specific wavelengths of the electromagnetic spectrum — not just visible light, but also near-infrared and other spectral bands. Plants, soils, and moisture each reflect light differently depending on their condition and composition. This subtle variance, invisible to the naked eye, becomes gold dust to archaeologists. Buried walls, ditches, or pits disturb surface vegetation just enough to leave faint spectral traces — crop marks, soil marks — which MSI can detect with startling accuracy. ...