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Journal of Archaeological Science 34 (2007) 1702e1712http://www.elsevier.com/locate/jas
Combining photogrammetry and laser scanning for the recordingand modelling of the Late Intermediate Period site of
Pinchango Alto, Palpa, Peru
Karsten Lambers a,*, Henri Eisenbeiss b, Martin Sauerbier b, Denise Kupferschmidt a,Thomas Gaisecker c, Soheil Sotoodeh b, Thomas Hanusch b
a German Archaeological Institute, Commission for Archaeology of Non-European Cultures (KAAK), Endenicher Str. 41, D-53115 Bonn, Germanyb ETH Zurich, Institute of Geodesy and Photogrammetry, Wolfgang-Pauli-Str. 15, CH-8093 Zurich, Switzerland
c Riegl Laser Measurement Systems GmbH, Riedenburgstr. 48, A-3580 Horn, Austria
Received 12 July 2006; received in revised form 1 December 2006; accepted 5 December 2006
This paper describes the 3D modelling of Pinchango Alto, Peru, based on a combination of image and range data. Digital photogrammetryand laser scanning allow archaeological sites to be recorded efficiently and in detail even under unfavourable conditions. In 2004 we documentedPinchango Alto, a typical site of the hitherto poorly studied Late Intermediate Period on the south coast of Peru, with the aim of conductingspatial archaeological analyses at different scales. The combined use of a mini helicopter and a terrestrial laser scanner, both equipped witha camera, allowed a fast yet accurate recording of the site and its stone architecture. In this paper we describe the research background, the3D modelling based on different image and range data sets, and the resulting products that will serve as a basis for archaeological analysis. 2006 Elsevier Ltd. All rights reserved.
Keywords: 3D modelling; Laser scanning; Photogrammetry; Andes; Nasca; Late Intermediate Period
The region of Nasca and Palpa on the south coast of Peru isfamous for the Nasca culture of the Early Intermediate Period(approximately 200 BCeAD 650; see Table 1) with its poly-chrome ceramics, fancy textiles, and large-scale geoglyphsin the desert in-between the fertile river oases (Silvermanand Proulx, 2002). In contrast, the Late Intermediate Period(hereafter LIP; approximately AD 1000e1450) in this regionis little known archaeologically. Before the start of a recentproject (Conlee, 2000), few LIP sites had been studied, themost prominent being Huayur or Ciudad Perdida in the SantaCruz valley (Alfaro de Lanzone, 1974e75; Ojeda, 1981;Orefici, 1993). The size of Huayur, its hidden location, and
* Corresponding author. Tel.: 49 1888 771 220; fax: 49 1888 771 249.E-mail address: email@example.com (K. Lambers).
0305-4403/$ - see front matter 2006 Elsevier Ltd. All rights reserved.doi:10.1016/j.jas.2006.12.008
the considerable amount of stone architecture and ceramicsis typical of LIP sites in the Nasca region and presents a majorchallenge to archaeological documentation.
Since 1997, the Nasca-Palpa Archaeological Project directedby Markus Reindel and Johny Isla has been investigating theprehispanic cultural history of the Grande, Palpa, and Viscasvalleys in the northern part of the Nasca drainage (Fig. 1)(Lambers, 2006; Reindel and Gruen, 2006). While large scaleexcavations focussed on sites of the Paracas and Nasca cultures(Isla and Reindel, 2006; Isla et al., 2003; Reindel and Isla, 2001),the aim of an extensive settlement survey was to document ar-chaeological sites from all prehispanic periods in the three val-leys (Isla and Reindel, 2005; Reindel et al., 1999). In the courseof this work, about 140 LIP sites (out of a total of 735 sites) wererecorded in a study area of 300 km2. The presence of large set-tlements and agricultural terraces suggests that the Palpa regionreached a demographic peak during the Late Intermediatemailto:firstname.lastname@example.org://http://www.elsevier.com/locate/jas
1703K. Lambers et al. / Journal of Archaeological Science 34 (2007) 1702e1712
Period, fostered by more humid conditions than in earlier andlater periods (Eitel et al., 2005; Machtle et al., 2006).
One of the most prominent LIP sites in the vicinity of Palpais Pinchango in the foothills of Cerro Pinchango between theGrande and the Palpa rivers. Its upper part, Pinchango Alto, islocated on a rocky spur and difficult to access (Fig. 2). As anexemplary LIP site in the Palpa region, it was decided to doc-ument Pinchango Alto using current geomatic technologies(Reindel and Isla, 2000). The aim was to create a high resolu-tion textured 3D model of the site that would be used for ar-chitectural, functional, and contextual archaeological studies.During the 2004 field season, funding provided by the GermanFederal Ministry of Research and Education (BMBF), Bonn,and the generous cooperation of Riegl GmbH, Horn, Austria,allowed the site to be documented by two novel recording sys-tems: an autonomous model helicopter as camera platform forthe acquisition of aerial images (Eisenbeiss et al., 2005, 2006;Eisenbeiss and Zhang, 2006) and a Riegl LMS Z420i laserscanner with integrated camera providing terrestrial range andimage data (Gaisecker, 2006). In this paper we focus on thecombined processing and analysis of three data sets e aerialimages, terrestrial images, and terrestrial scan data e and the3D modelling of the site and its architecture.
In the following, the site is presented, and previous archaeo-logical research in the region of Nasca and Palpa is briefly
Chronological table for the south coast of Peru (cp. Unkel, 2006)
Approximate dates Period Ceramic style
1450e1532 A.D. Late Horizon Inca
1000e1450 A.D. Late Intermediate Period Ica-Chincha
650 A.D.e1000 A.D. Middle Horizon Loro/Chakipampa200 B.C.e650 A.D. Early Intermediate Period Nasca
800 B.C.e200 B.C. Early Horizon Ocucaje
1800 B.C.e800 B.C. Formative Period Pernil
reviewed in order to define requirements for the documentationof LIP sites. The combined processing of range and image dataand the generation of different 3D models of Pinchango Alto isthen described next. The underlying aim of this paper is twofold:1) to present the LIP site of Pinchango Alto in its archaeologicalcontext; and 2) to show how modern electro-optical recordingtechnology can support the flexible and efficient documentation,modelling and analysis of archaeological sites.
2. Pinchango Alto and the Late Intermediate Period in theregion of Palpa and Nasca
The Ro Grande de Nasca drainage on the southern coast ofmodern Peru is formed by the Grande river and its eight afflu-ents. Over the course of the millennia the rivers have cut deepravines into the Andean foothills and the pediments to theirwest, thus forming narrow river valleys separated by ridgesand plateaus. Today the region has a very arid climate with al-most no annual precipitation. Agriculture is only possible onthe valley bottom and is dependent upon the water whichthe rivers carry from the high Andes where they are fed by sea-sonal rainfalls.
Fig. 2. The architectural remains of Pinchango Alto as seen from the north.
Fig. 1. The archaeological site of Pinchango Alto near Palpa on the south coast of Peru (coordinates: UTM 18S, WGS 84).
1704 K. Lambers et al. / Journal of Archaeological Science 34 (2007) 1702e1712
Archaeological site surveys in the region (Browne, 1992;Browne and Baraybar, 1988; Isla and Reindel, 2005; Reindelet al., 1999) have shown that larger, permanent settlementsfirst appeared during the Formative Period (Reindel and Isla,2006) and increased in number during the Early Horizonand the time of the Nasca culture (Table 1). People livedmainly in small settlements with adobe buildings close to cul-tivable land. After a partial abandonment during the MiddleHorizon (approximately AD 650e1000) the valleys saw a ma-jor resettlement during the Late Intermediate Period. Theabundant ceramic sherds on the surface of many settlementsshow, through comparison to pottery from the Ica and Nascavalleys, that the LIP sites in the Grande and Palpa valleysformed part of a larger cultural region along the south coast(Conlee, 2000; Menzel, 1976; Vaughn et al., 2006). The pop-ulation grew again to a level equal to or higher than during theNasca period. At least in the northern part of the drainage LIPsettlements were fewer yet larger than in earlier periods. Mostsites were located well above earlier zones of habitation, alongthe slopes as well as on remote plateaus and spurs of the An-dean foothills and at a considerable distance from any modernwater source. This settlement pattern is remarkably differentfrom previous periods, and its social and economic back-ground has yet to be investigated in detail. As recent researchindicates, LIP climate appears to have been more humid withreliable summer rains (Eitel et al., 2005; Machtle et al., 2006).Apparently this allowed water to be caught and stored bymeans of terracing in side valleys that today are dry. The avail-ability of local water sources would have increased the defen-sive potential of LIP sites. Whether or not this was a majorconcern to the ancient inhabitants of Pinchango Alto and othercontemporaneous sites is as yet unclear, however.
Their remote location has saved many LIP settlements fromsevere looting leaving them in a relatively good state of pres-ervation. Sites are composed of different architectural features,like narrow platforms with revetments of stones (along slopesand in steep gullies of hills), small agglutinated rooms, com-pounds with larger rooms, and open spaces. The clusteringof these structures within certain parts of the sites points to in-ternal divisions perhaps reflecting social stratification or eco-nomic specialisation. Most LIP sites have at least one, butnormally several large grinding stones with smoothed sur-faces, indicating prolonged use, that are distributed unevenlyt