Satellite and Aerial Remote Sensing

Aerial and satellite remote sensing detect archaeological sites and landscapes from above, using cropmarks, soilmarks, multispectral imagery, and lidar to reveal features invisible at ground level.

Definition

The detection and mapping of archaeological features and landscapes from aerial and satellite platforms, including photographic, multispectral, and lidar data, often revealing patterns not visible on the ground.

Scope

This topic covers archaeological remote sensing from aircraft, drones, and satellites: the interpretation of cropmarks, soilmarks, and shadow marks in aerial photographs, the use of multispectral and thermal satellite imagery, and airborne lidar, which penetrates vegetation to map terrain and features beneath forest canopy. It addresses how these datasets are processed and verified.

Core questions

• How do cropmarks and soilmarks reveal buried features from the air?
• What do multispectral and thermal satellite data add?
• How does lidar map features beneath vegetation?
• How are remotely sensed features verified on the ground?

Key theories

Cropmark and soilmark detection

The principle that buried ditches and walls alter plant growth and soil color, producing marks visible from the air under suitable conditions of crop, soil, and light.

Airborne lidar mapping

The use of laser scanning from aircraft to build detailed terrain models that can be filtered to remove vegetation, exposing earthworks and features under forest, as famously at Maya sites.

History

Aerial archaeology began with balloon and aircraft photography in the early 20th century, with pioneers such as O. G. S. Crawford systematizing the interpretation of cropmarks. Satellite imagery and multispectral analysis expanded the field from the late 20th century, and airborne lidar since the 2000s has transformed survey in forested regions such as Mesoamerica and Southeast Asia.

Debates

Scale of discovery versus verification

Remote sensing, especially lidar, can reveal vast numbers of features quickly, prompting debate over how such discoveries should be verified, dated, and interpreted without overstating densely mapped landscapes.

Key figures

• Sarah Parcak
• D. R. Wilson
• Arlen Chase
• Diane Chase

Seminal works

• parcak2009
• wilson2000
• chasechase2011

Frequently asked questions

What are cropmarks?

Cropmarks are differences in the height, color, or ripening of crops caused by buried features such as ditches or walls affecting how plants grow, making the features visible from the air.

Why is lidar important in archaeology?

Lidar can be processed to strip away vegetation and reveal the bare ground surface, exposing earthworks, terraces, and structures hidden beneath dense forest.