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Velocity Analysis in Archaeological Ground‐Penetrating Radar Studies
Author(s) -
CONYERS LAWRENCE B.,
LUCIUS JEFFREY E.
Publication year - 1996
Publication title -
archaeological prospection
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.785
H-Index - 38
eISSN - 1099-0763
pISSN - 1075-2196
DOI - 10.1002/(sici)1099-0763(199603)3:1<25::aid-arp39>3.0.co;2-u
Subject(s) - ground penetrating radar , geology , radar , excavation , measured depth , reflection (computer programming) , radar horizon , remote sensing , geodesy , radar imaging , radar engineering details , geophysics , computer science , geotechnical engineering , telecommunications , programming language
In ground‐penetrating radar (GPR) investigations of archeological sites, the accurate conversion of two‐way travel times to distance or depth can be made only if radar wave velocities are known. Because radar data are typically collected in a manner that does not facilitate the determination of velocity, special efforts must be given to measure the speed of radar waves in the subsurface. Field tests can be performed on objects at known depths where radar wave travel times can be measured directly. These tests can be integrated with the correlation of known stratigraphic units to radar reflections in order to confirm the velocity measurements and map subsurface interfaces. Transillumination tests can be performed in adjoining excavations in order to determine velocity variations with depth. Common mid‐point type tests are helpful in estimating near‐surface velocity changes but are less valuable in determining velocity at greater depth. Data from these tests can be used to derive velocity gradient curves and identify possible buried reflection surfaces. The integration of many velocity tests can assure accurate conversions of travel time to depth over a large study area. Mapping of surfaces or features in true depth as opposed to radar travel time can confirm the correlations of GPR reflections to known subsurface units and enhance the understanding of an archaeological site.