PHOTOGRAMMETRIC SURVEY WITH FISHEYE LENS FOR THE CHARACTERIZATION OF THE LA SASSA CAVE

Abstract. The survey of ancient cave can generally be performed by traditional topographic methods that allow also its georeferencing in a global reference frame; some difficulties may arise when there are narrow tunnels that do not consent the use of a total station or a terrestrial laser scanner. In such cases a visual-based approach can be used to produce, both the followed path and the 3D model of the hypogeal environment. A prompt photogrammetric survey has been used to reconstruct the morphology of the La Sassa Cave, situated in the municipality of Sonnino (Latina), in the lower Lazio region. In this cave, a very large quantity of Pleistocene animal bones was found, together with several fragments of Copper Age human bones and Bronze Age impasto potsherds. The survey was carried out using a DSLR full frame camera Nikon D800E with a Nikkor 16mm fisheye lens pre-calibrated. During the acquisition, several targets were measured in order to contain the deformations model. The photogrammetric model has been georeferenced using 3 GCPs positioned outside the cave entrance where a double frequency GNSS receiver has acquired data in static session mode.

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THREE-DIMENSIONAL SURVEY OF GUATTARI CAVE WITH TRADITIONAL AND MOBILE PHONE CAMERAS

ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences ◽

10.5194/isprs-archives-xlii-2-w11-37-2019 ◽

2019 ◽

Vol XLII-2/W11 ◽

pp. 37-41 ◽

Cited By ~ 2

Author(s):

L. Alessandri ◽

V. Baiocchi ◽

S. Del Pizzo ◽

F. Di Ciaccio ◽

M. Onori ◽

...

Keyword(s):

Mobile Phone ◽

Reference System ◽

3D Model ◽

Three Dimensional ◽

Laser Scanner ◽

Terrestrial Laser Scanner ◽

Fisheye Lens ◽

Gnss Receiver ◽

Double Frequency

Abstract. Sometimes, the georeferencing of a cave in the global reference system can be challenging. Some difficulties may arise when narrow passages do not allow the use of classical topographic equipment or a terrestrial laser scanner. In these specific cases, the surveyor can employ a visual-based approach to produce both the followed path and the 3D model of the hypogeum. The report we are presenting is the result of a survey in the Guattari cave carried out using images taken by a Huawei P9 mobile phone and a Nikon D800E camera with a 16&thinsp;mm fisheye lens. Several targets were measured in order to contain the deformation of the models. Three GCPs located just outside the cave have been used to georeference the models. The data have been acquired by a double frequency GNSS receiver in static session mode. The comparison between the two models shows a substantial concordance only in the area outside the cave where the GCPs were measured. In the innermost areas, the two models differ by as much as two meters.

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Evaluation of geometrical benchmark artifacts containing multiple overhang lengths fabricated using material extrusion technique

JOURNAL OF MECHANICAL ENGINEERING AND SCIENCES ◽

10.15282/jmes.14.3.2020.28.0573 ◽

2020 ◽

Vol 14 (3) ◽

pp. 7296-7308

Author(s):

Siti Nur Humaira Mazlan ◽

Aini Zuhra Abdul Kadir ◽

N. H. A. Ngadiman ◽

M.R. Alkahari

Keyword(s):

3D Model ◽

Laser Scanner ◽

Dimensional Accuracy ◽

Fused Deposition Modelling ◽

Layer By Layer ◽

Fused Deposition ◽

Layer Technique ◽

Subtractive Manufacturing ◽

Manufacturing Features ◽

Layer Problem

Fused deposition modelling (FDM) is a process of joining materials based on material entrusion technique to produce objects from 3D model using layer-by-layer technique as opposed to subtractive manufacturing. However, many challenges arise in the FDM-printed part such as warping, first layer problem and elephant food that was led to an error in dimensional accuracy of the printed parts especially for the overhanging parts. Hence, in order to investigate the manufacturability of the FDM printed part, various geometrical and manufacturing features were developed using the benchmarking artifacts. Therefore, in this study, new benchmarking artifacts containing multiple overhang lengths were proposed. After the benchmarking artifacts were developed, each of the features were inspected using 3D laser scanner to measure the dimensional accuracy and tolerances. Based on 3D scanned parts, 80% of the fabricated parts were fabricated within ±0.5 mm of dimensional accuracy as compared with the CAD data. In addition, the multiple overhang lengths were also successfully fabricated with a very significant of filament sagging observed.

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A proposal of a 3D segmentation tool for HBIM management

Applied Geomatics ◽

10.1007/s12518-021-00373-4 ◽

2021 ◽

Author(s):

Vincenzo Barrile ◽

Antonino Fotia

Keyword(s):

Cultural Heritage ◽

3D Model ◽

Laser Scanner ◽

Perfect Reconstruction ◽

Building Information Modelling ◽

Information Modelling ◽

South Italy ◽

Building Information ◽

Heritage Building ◽

Modelling Techniques

AbstractThere are several studies related to the cultural heritage digitization through HBIM (Heritage Building Information Modelling) techniques. Today, BIM (Building Information Modelling) software cannot represent old buildings with complex prominent and particularly detailed architecture perfectly, and multiple software are combined to obtain the buildings’ representation. In this paper, in order to find an alternative way of replicating the complex details present in antique buildings, a new methodology is presented. The methodology is based on a process of direct insertion of various 3D model parts (.obj), into a BIM environment. These 3D model elements, coming from the points cloud segmentation (from UAV and Laser Scanner), are transformed in intelligent objects and interconnected to form the smart model. The methodology allows to represent detail of the objects that make up an element of cultural heritage, although not standardizable in shape. Although this methodology allows to ensure a perfect reconstruction and digital preservation and to represent the different “defects” that represent and make unique a particular object of cultural heritage, it is not however fast compared with the traditional phases of point cloud tracing and more software are necessary for data processing. The proposed methodology was tested on two specific structures’ reconstruction in Reggio Calabria (South Italy): the Sant’Antonio Abate church and the Vitrioli’s portal.

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Aquatic Radiocarbon Reservoir Offsets in the Southeastern Baltic

Radiocarbon ◽

10.2458/azu_rc.57.18447 ◽

2015 ◽

Vol 57 (4) ◽

pp. 539-556 ◽

Cited By ~ 19

Author(s):

Gytis Piličiauskas ◽

Carl Heron

Keyword(s):

Stable Isotope ◽

Bronze Age ◽

Radiocarbon Dating ◽

Bone Collagen ◽

Curonian Lagoon ◽

Human Bones ◽

Ceramic Vessel ◽

Pike Perch ◽

Ceramic Vessels ◽

Ams Dates

The aim of this article is to discuss radiocarbon dating offsets due to freshwater and marine reservoir effects (FRE and MRE, respectively) in the southeastern Baltic. Thirty-six 14C dates from Lithuanian coastal and inland Subneolithic, Neolithic, and Bronze Age sites as well as two Mesolithic-Neolithic cemeteries are presented here. Accelerator mass spectrometry (AMS) dates, sometimes paired or tripled, have been obtained on samples of various origin, foodcrusts, or visible charred deposits adhering to the surfaces of ceramic vessel walls were also dated and investigated for stable isotope signals. The results argue for a significant freshwater component in the food processed in ceramic vessels during the Subneolithic and Neolithic. Paired dating of ungulate and human bones at the Spiginas and Donkalnis cemeteries (6300–1900 cal BC) does not suggest an FRE, although stable isotope data on human bone collagen strongly suggest a large input of freshwater food in the diet. An FRE in the order of 320–510 yr was estimated for the Šventoji paleolagoon around 3000 cal BC. At the same time, the FRE of the Curonian Lagoon could be larger as implied by large apparent 14C ages of modern pike-perch (981 ± 30 BP) and bream (738 ± 30 BP) bones as well as “foodcrust” offsets (650–530 yr) at Nida (3500–2500 cal BC). An MRE of 190 ± 43 yr was estimated for the southeastern coast of the Littorina Sea according to offsets between dates of seal bones and terrestrial samples at Nida and Šventoji. Any FRE at Lake Kretuonas remains uncertain due to the limited work to date.

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Isotopes, Plants, and Reservoir Effects: Case Study from the Caspian Steppe Bronze Age

Radiocarbon ◽

10.1017/s0033822200047408 ◽

2012 ◽

Vol 54 (3-4) ◽

pp. 749-760 ◽

Cited By ~ 13

Author(s):

N Shishlina ◽

E Zazovskaya ◽

J van der Plicht ◽

V Sevastyanov

Keyword(s):

Bronze Age ◽

Alternative Explanation ◽

Bone Collagen ◽

Human Diet ◽

Human Bones ◽

Animal Bone ◽

Different Types ◽

C And N ◽

East And West

Bronze Age human and animal bone collagen from several steppe Bronze Age cultures (i.e. Early Catacomb, East and West Manych Catacomb, and Lola cultures) shows large variations in δ13C and δ15N values. In general, we observed that the older the sample, the lower the δ13C and δ15N values. We hypothesize that more positive values of δ13C and δ15N are caused by change in diet and a more arid climate. For ancient sheep during drier periods of the Early Catacomb, East and West Manych Catacomb, and Lola cultures, we observed 2 groups with different C and N isotopic compositions, reflecting consumption of different types of fodder. During periods of aridization, C4 and C3 plants with high δ15N values appeared in the vegetation, also influencing bone collagen values. Human bones show reservoir effects, caused by aquatic diet components. These effects can be quantified by paired dating of human bone and associated terrestrial samples. Reservoir corrections have revised chronologies for the region. Some paired dates do not reveal reservoir effects. This can be explained in 2 alternative ways. One is that the human diet did not include aquatic components; rather, the diet was based on C3 vegetation with high δ15N values (13–15‰), and flesh/milk of domesticated animals. An alternative explanation is that humans consumed food from freshwater resources without reservoir effects.

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A Moving 3D Laser Scanner for Automated Underbridge Inspection

10.20944/preprints201710.0172.v1 ◽

2017 ◽

Author(s):

Marco Tarabini ◽

Hermes Giberti ◽

Silvio Giancola ◽

Matteo Sgrenzaroli ◽

Remo Sala ◽

...

Keyword(s):

Measurement Uncertainty ◽

Numerical Simulations ◽

Relative Motion ◽

Reference System ◽

Complete System ◽

Laser Scanner ◽

Bridge Model ◽

Fixed Reference ◽

Scanning Head

Recent researches proved that the underbridge geometry can be reconstructed by mounting a 3D laser scanner on a motorized cart travelling on a walkway located under the bridge. The walkway is moved by a truck and the accuracy of the bridge model depends on the accuracy of the trajectory of the scanning head with respect to a fixed reference system. In this paper, we describe the metrological characterization of a method that uses non-contact systems to identify the relative motion of the cart with respect to the walkway; the orientation of the walkway with respect to the bridge is determined using inclinometers and optical rails, while the position of the truck with respect to the bridge is measured using a conventional odometer.  The measurement uncertainty of the proposed system was initially evaluated by numerical simulations and successively verified by experiments in laboratory conditions. The complete system has then been tested in operative conditions; the validity of the proposed approach has been demonstrated by comparing the geometry of buildings reconstructed with the proposed system with the geometry obtained with a static scan. Results evidenced that the errors are approximately 6 mm.

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