Wednesday, May 12, 2010

Mapping Ancient Civilization - New York Times

"For a quarter of a century, two archaeologists and their team slogged through wild tropical vegetation to investigate and map the remains of one of the largest Maya cities, in Central America. Slow, sweaty hacking with machetes seemed to be the only way to discover the breadth of an ancient urban landscape now hidden beneath a dense forest canopy...."



Source: http://www.nytimes.com/2010/05/11/science/11maya.html

Interesting article in NYTimes!

Sunday, May 9, 2010

Spatial analysis of the Bronze Age sites of the region of Paphos in southwest Cyprus with the use of Geographical Information Systems - CAA

Surface analysis is also a very popular research area in GIS/Archaeology. I want to write more about Least-Cost Analysis in GIS later.

This work was mede by:
University of Cyprus, Archaeological Research Unit and Laboratory of Geophysical – Satellite Remote Sensing and Archaeo-environment, Institute for Mediterranean Studies, Foundation for Research and Technology




Part of Introcuction:

"The paper aims to study the Bronze Age site
distribution in the region of Paphos in SW Cyprus in
order to interpret site patterns. In the context of the
Paphos pilot project, entitled, “A long-term response
to the need to make modern development and the
preservation of the archaeo-cultural record mutually
compatible operations” (IACOVOU et al. 2009),
spatial analysis was performed, with the use of
Geographic Information Systems (GIS), on sites of
the Early, Middle and Late Cypriot period (3rd and
2nd millennium BC) that have been reported from
the region to this date...."

Underwater 3D shape reconstruction by fringe projection - CAA

Hallo everybody!

Sorry for the long time...

My second fovourite presentatiton was from CAA: "Underwater 3D shape reconstruction by fringe projection"
Great research at the University of Calabria, Italy (Bianco, G., Bruno, F., Muzzupappa, M., Luchi, M.L.).
Our Institute accomplished a big camera calibration project for underwater archaeological documentation, which was an interesting topic.


Part of Introcuction:

"....In this work, we have tested the effectiveness of a
whole-field structured light technique, based on
fringe projection, in underwater environment. The
Fringe Projection Technique (FPT) is widely used in
air (RASTOGI and GORTHI, 2010), and consists of
projection and acquisition of sinusoidal patterns on
the object (in the simplest case, one pattern is
enough). The system is composed by a video
projector and a digital camera, and the geometrical
setup is based on the principle of optical
triangulation. The recorded images are analyzed to
evaluate the phase-map of the object - which contains
the height information - with a signal processing
technique such as Fourier Transform (FT) , Wavelet
Transform (WT) , Windowed Fourier Transform
(WFT) , Spatial Phase Detection (SPD) or Phase
Stepping (PS). Any of these techniques of phase
measurement provides a discontinuous phase map of
the object (wrapped): so it becomes necessary to use
phase unwrapping in order to obtain a continuous
phase distribution (SURREL, 1998). By knowing the
intrinsic (focal distances, coordinates of the principal
points, and distortions) and extrinsic (relative
positions between the optical devises) parameters,
one can calculate the point clouds from the
triangulation between a optical ray of the camera (at
i,j pixel with phase value φi,j) and the relative plane
in the projector frame at the same phase value...."