From radar to satellite remote sensing, modern archaeology tools give researchers new insights...
Movies such as “Indiana Jones” and “Tomb Raider” may have forever imprinted on the collective psyche the idea of the archaeologist as a swashbuckling rogue adventurer. The popular image of archaeological tools may be shovels and brushes and knives and maybe even a whip, but what are archaeologists today actually using as they rediscover and interpret the past? There may be no shootouts, ancient traps, or mummies come to life, but archaeological researchers have their own high tech set of tools to ensure they can both preserve and analyze artifacts of civilizations past. From innovative forms of radar to laser mapping and space archaeology, here are the top four tools of the modern archaeological field.
Radar is a staple of archaeological research, used to make enormous discoveries and clear-up historical mysteries. Most recently, Bek’s chapel, one of England’s most important medieval buildings, was rediscovered, and radar was used to reimagine what it once looked like, aiding in reconstruction of the site’s unearthed masonry, stained glass, and black plaster floor — all of which was destroyed with gunpowder in the mid-seventeenth century. Another recent discovery? A previously undiscovered chamber in King Tut’s tomb: a possible location of the still-missing remains of Queen Nefertiti.
So how were these discoveries made? Used across a number of fields including environmental studies and civil engineering, ground-penetrating radar (GPR) is a system that performs a type of geophysical study which can scan, map, and record information about the Earth’s subsurface. The most significant benefit of this type of study, when it comes to archaeology, is that it’s entirely non-intrusive and nondestructive.
GPR employs high-frequency (usually polarized) radio waves at UHF/VHF frequencies, which are emitted into the ground. The pulses are reflected, refracted, or scattered back to the surface when encountering the differing permittivities of buried objects or boundaries between materials; a receiving antenna records the variations in the return signal. This works very similarly to seismology but employs electromagnetic energy rather than acoustic energy. As GPR can be used from above the ground, it’s excellent for use-cases like the unearthed medieval chapel, where the exact location has been lost, and where researchers may need to scan a broad area for traces.
Sending out pulses and taking measurements gets you a lot of raw data, not a map. Luckily, software solutions can turn data arrays into visual maps ready for analysis. A geographic information system (GIS) allows researchers to manage and display all types of geographic and spatial data. As a field, archaeology was an early adopter of GIS mapping, and as geospatial tools have become more powerful, the software has only allowed archaeology to evolve.
GIS is the software component to LiDAR technology that allows for efficient use of remote sensing technologies to map areas of archaeological interest, but it can also be used for predictive mapping and to provide new perspectives on well-researched sites. In predictive applications, researchers can incorporate data from multiple sources — historical maps, current landscape, and known information about past inhabitants — to predict sites that may have held cultural, historical, or agricultural relevance.
Using software tools can also shed new light on previously collected and analyzed data. To understand more of the complex Maya civilization, researchers have used GIS to aggregate known data — on which structures were built and on their selected locations — in order to analyze why choices may have been made. With a little prior knowledge and data, GIS software can be just the tool to shed new light on ancient civilizations.
Want to broaden the scope of what we can scan and map even further? Let’s get satellites involved. Space archaeology, or satellite remote sensing, stands to revolutionize archaeological techniques by searching the Earth’s surface for hints of buried features from orbit. The origins of this technique can be traced from early-twentieth-century aerial photography, used to identify features from a distance. Beyond visual imaging, it also employs multispectral and hyperspectral scanners, which obtain the electromagnetic spectrum for each pixel in an image, thermal infrared multispectral scanners (TIMS), microwave radar, and color infrared film.
Currently, resolution for satellite imagery is capped at approximately one foot, but resolutions down to one centimeter are in development. To aggregate data in an easily parsed image, scientists often assign “false color” to different types of features. Scanning methods such as LiDAR and radar are currently employed in satellite mapping, and there are only more developments to come.