So sánh phương pháp

	Magnetometry Survey	Structure from Motion
Lĩnh vực	Khảo cổ học	Khảo cổ học
Họ	Process / pipeline	Process / pipeline
Năm ra đời	1958	2012
Người khởi xướng	Martin Aitken & John Belshé (first archaeological magnetometer survey, 1958)	Computer-vision SfM adapted for archaeological recording (popularized with low-cost photogrammetry, c. 2010s)
Loại	Geophysical prospection pipeline mapping subsurface magnetic anomalies	Image-based 3D reconstruction pipeline for site and artifact recording
Công trình gốc	Aspinall, A., Gaffney, C., & Schmidt, A. (2008). Magnetometry for Archaeologists. AltaMira Press. ISBN: 9780759111066	Renfrew, C., & Bahn, P. (2016). Archaeology: Theories, Methods, and Practice (7th ed.). Thames & Hudson. ISBN: 9780500292105
Tên gọi khác	Archaeological Magnetometry, Magnetic Gradiometer Survey, Fluxgate Gradiometry, Magnetic Prospection	SfM Photogrammetry, Structure-from-Motion Modeling, Image-Based 3D Recording, Multi-View Photogrammetry
Liên quan	2	2
Tóm tắt	Magnetometry survey is a non-invasive geophysical technique that maps buried archaeological features by detecting the tiny variations they produce in the Earth's magnetic field. Many human activities alter the magnetic properties of the ground: burning enhances the magnetism of soil in hearths and kilns, while pits and ditches filled with topsoil are more magnetic than the surrounding subsoil, and stone walls may be less magnetic. A magnetometer carried across a gridded survey area records these faint anomalies, which are processed into a plan-view image revealing the shape and arrangement of subsurface features without digging. First applied archaeologically by Martin Aitken and John Belshé in 1958 and developed into modern fluxgate and caesium gradiometry, magnetometry is among the fastest and most informative prospection methods, as detailed in Aspinall, Gaffney, and Schmidt's standard reference and in general texts such as Renfrew and Bahn.	Structure from Motion (SfM) is a photogrammetric technique that reconstructs three-dimensional models of archaeological subjects from sets of ordinary overlapping photographs. Borrowed from computer vision, it works by automatically finding the same physical points in many images, solving simultaneously for where each photograph was taken and where those points lie in space, and then building a dense point cloud, a meshed surface, and a photo-textured model. Because it needs only a camera and overlapping coverage, SfM has made high-resolution 3D recording of excavation surfaces, standing structures, artifacts, and whole landscapes (often from drones) fast and affordable. Scaled and georeferenced with control points, the resulting models integrate with GIS for measurement, analysis, and archiving, making SfM a core tool of digital field recording as reflected in Renfrew and Bahn and in the GIS workflows described by Conolly and Lake.