Theoretical and practical aspects of
archaeological orthoimaging

dc.contributor.author	Μαυρομάτη, Δήμητρα	el
dc.contributor.author	Πέτσα, Έλλη	el
dc.contributor.author	Καρράς, Γιώργος	el
dc.date.accessioned	2015-05-24T22:02:15Z
dc.date.available	2015-05-24T22:02:15Z
dc.date.issued	2015-05-25
dc.identifier.uri	http://hdl.handle.net/11400/11095
dc.rights	Αναφορά Δημιουργού-Μη Εμπορική Χρήση-Όχι Παράγωγα Έργα 3.0 Ηνωμένες Πολιτείες	*
dc.rights.uri	http://creativecommons.org/licenses/by-nc-nd/3.0/us/	*
dc.source	http://www.isprs.org	en
dc.subject	Distortion
dc.subject	Bundle
dc.subject	Δέσμη
dc.subject	Παραμόρφωση
dc.subject	Αρχαιολογία
dc.subject	Archaeology
dc.title	Theoretical and practical aspects of archaeological orthoimaging	en
heal.type	journalArticle
heal.classification	Topography
heal.classification	Geodesy
heal.classification	Τοπογραφία
heal.classification	Γεωδαισία
heal.classificationURI	http://skos.um.es/unescothes/C04078
heal.classificationURI	http://id.loc.gov/authorities/subjects/sh85053969
heal.classificationURI	N/A-Τοπογραφία
heal.classificationURI	N/A-Γεωδαισία
heal.language	en
heal.access	free
heal.publicationDate	2002
heal.bibliographicCitation	Mavromati D., Petsa E. and Karras G. (2002) Theoretical and practical aspects of archaeological orthoimaging. "Photogrammetry & Remote Sensing", 34 (B5), p.413-418	en
heal.abstract	Orthophotos are a standard requirement in archaeological documentation; yet they differ in several respects from aerial orthoimaging. The required large scales of end-products call for close-range photography, usually taken from low altitude or with raised cameras for horizontal recording. Special camera platforms need to be devised to this effect, such as the flexible low-cost devices (small balloon; adapted fishing-rod) used here. With such ‘unstable’ platforms image tilt, recording distances and overlap are not easily controlled, hence irregular strip geometries are expected. Besides, the non-metric cameras used have unknown inner orientation and often large lens distortion. Our experiences with such bundle adjustments are discussed. Precise surface description is a further issue, more than often involving modeling of rough surfaces with abrupt changes, discontinuities and protruding parts. Examples from different projects illustrate the authors’ experience as regards data collection allowing generation of ‘vertical triangles’, indispensable for creating ‘true orthophotos’ with commercial software. A final aspect addressed in this contribution concerns the exploitation of the numerous existing line drawings of sites. This graphical information, mostly planar, might be extensively used as exclusive ground control to produce orthomosaics for innumerable sites, at least as basic archival documentation. Rather than performing purely planimetric strip adjustment, an approach is tested here which additionally makes use of suitably weighted model elevations of such planar ‘control points’ derived from the maps. The presented results show an increase in accuracy, thus indicating that in several cases existing 2D information may help minimise, or even eliminate, the need for control surveys. The discussed aspects of archaeological orthophotography are illustrated with examples from various Greek sites, namely the parodoi of the ancient theatre of Sparta, the ancient castle of Aigosthena, the ancient theatre of Zea in Piraeus and an archaic site of Zeus in Athens.	en
heal.journalName	Photogrammetry & Remote Sensing	en
heal.journalType	peer-reviewed
heal.fullTextAvailability	true