Tn. Ladefoged et al., GIS-BASED IMAGE-ENHANCEMENT OF CONDUCTIVITY AND MAGNETIC-SUSCEPTIBILITY DATA FROM URETURITURI PA AND FORT RESOLUTION, NEW-ZEALAND, American antiquity, 60(3), 1995, pp. 471-481
Two geographic information system (GIS) techniques for displaying, ana
lyzing, and interpreting geophysical data were recently applied at two
archaeological sites in northern New Zealand; a pre-European Maori pa
(fortification), and a late nineteenth-century European fortification
. A GIS was used to stretch and filter the conductivity data from the
pa to accentuate subtle contrasts and clearly delineate boundaries bet
ween areas with contrasting conductivity readings. Magnetic susceptibi
lity data and two different bands of conductivity data from the histor
ic fort were used as input for a GIS-based unsupervised classification
. The classification delineated five spatial entities, several of whic
h corresponded to known archaeological features. The interpretability
of the geophysical data in in relation to conventional visual analysis
of conductivity contour maps was enhanced through the use of the GIS
procedures outlined.