Financial support for this project was provided by
The Agency for Cultural Affairs of the Japanese Government

A Series of Photogrammetry forProtection of Syrian Cultural Heritage
Ancient Village of Northern Syria Vol 1
QALB LOZEH
By
Akira Tsuneki
Nobuya WatanabeSari Jammo
Research Center for West Asian Civilization,
University of Tsukuba
All rights reserved.
Printed in Tsukuba, Japan, 2017

Acknowledgements

All photographs used in this publication were taken by our friends who live in Idlib. Without
their effort, our project was never completed. We deeply thanks them who carried out
photography for our project regardless of serious danger in the great difficulty under the civil
war.

CONTENTS

1.

Qalb Lozeh photogrammetry project

Akira Tsuneki

1

2.

The process of making a 3D image of Qalb Lozeh

Sari Jammo

7

3.

3D reconstruction of Qalb Lozeh

Nobuya Watanabe

13

1.

Qalb Lozeh photogrammetry project
Akira Tsuneki

Since the beginning of the conflict in Syria in 2011 much cultural heritage has been lost or destroyed. All thearchaeologists who have been engaged in archaeological investigation in Syria are extremely concerned about thistragic situation, and felt something must be done to mitigate this situation. In response to this, the Agency for
Cultural Affairs, Government of Japan, provided financial support for safeguarding Syrian cultural heritage in 2015.
Therefore, the following actions were undertaken to investigate what could be done in the meantime: a) Researchon the situation within Syrian cultural heritage during the crises (2011 ‒ 2015), b) Public lectures and discussionof Syrian cultural heritage with the Japanese public in Tokyo, and c) Experts meeting with Syrian and Lebanesearchaeologists and UNESCO officers to facilitate safeguarding Syrian cultural heritage in Beirut. As a result, theAgency for Cultural Affairs proposed further financial support in safeguarding Syrian cultural heritage in 2016.
Consequently, the new project authorized by the Agency of Cultural Affairs focuses on: 1) Instruction of young
Syrians on the importance of Syrian cultural heritage, 2) Documentation of endangered Syrian cultural heritageand 3) Preparing manuals for people safeguarding cultural heritage in archaeological and heritage sites in Syria.
This book is a result of the second category, i.e. 2) Documentation of endangered Syrian cultural heritage. In
undertaking this important operation, it was necessary to first select a site in danger of destruction. The Universityof Tsukuba Archaeological Mission has been investigating an archaeological site named Tell el-Kerkh in Idlib since
1990, and is familiar with the world cultural heritage sites, “the Ancient Villages of Northern Syria”. These
important Roman and Byzantine architectural remains have been extensively damaged during the conflict. Our
mission heard about the partial destruction of important sites in this world cultural heritage group, such as St.
Simon, el-Bara, Serjira and others. These sites represent the Roman-Byzantine Villages of Northern Syria, andmembers of the mission determined that a documentation project for these sites should be instigated as soon as
possible before further destruction occurs. A project for the accurate documentation of these archaeological sites
will contribute a precise record that may be used for reconstruction should the sites be destroyed. This work isuseful not only for the recording and preservation of heritage sites but also reflects the scientific and academic focal
points of the research mission. As a result the site of Qalb Lozeh, one of the oldest churches in the Idlib area waschosen as the first target of a photographic survey for use in photogrammetric analysis and the creation of a 3D
image.
Qalb Lozeh ‫ﻗﻠﺐ ﻟﻮﺯﺓ‬36°10′9″N, 36°34′50″E

The Ancient Villages of Northern Syria are one of the Syrian World Heritage sites appointed by UNESCO in 2011.
This world heritage consists of over 700 ancient villages, dating to the Roman and Byzantine eras, located in thelimestone mountains of northwestern Syria in the Governorates of Idlib and Aleppo (Fig. 1).

1

Fig. 1 Location of Qalb Lozeh ‫ﻗﻠﺐ ﻟﻮﺯﺓ‬These limestone mountains sandwich the Orontes River.
Westward, the Ansariye Mountains extend to the north andsouth, and the mountainous districts such as the Zawiye
Mountains and Seman Mountains extend further to the eastside. The Ancient Villages are located and had been managed
in the limestone mountainous district of the Orontes eastbank (Fig. 2). These limestone mountains form anenvironmentally heterogeneous area with the western
Mediterranean seashore and the eastern Syrian Desert zone.
This area is comprised almost entirely of rocky limestone
however red soil outcrops resulting from weathered
limestone can be found here and there. This red soil zone
creates areas used for farming and villages. The precipitation
is approximately 500mm a year but the resulting groundwater
exits the mountainous area. Therefore, a river does not exist
in the vicinity and the vegetation mainly consists ofMediterranean trees such as olive, pistachio, fig, and oak as
Fig.2 Limestone mountains of NW Syria

well as grape vines.

Archeological investigation of the Limestone Mountains area began with, an investigation into Christian heritagearchitecture by M. de Vogüé (1865-1877) in the mid-19th century. Research on the Roman and Byzantine remains
has been pushed forward intermittently since then by H. C. Butler (1920), J. Mattern (1944), G. Tchalenko (1953)
and others in the early 20th century. In the late 20th century, O. Callot (1984), H. J. Marcillet-Jaubert, J. P. Sodini(1980), G. Tate (2013) and others investigated the limestone villages, clarifying the lifestyle and local history of
the Limestone Mountains. Their research revealed that the limestone mountainous district of northwestern Syria
2was prosperous due to its olive oil production from the 1st to 7th centuries AD. The acceptance and disseminationof Christianity in this region was also very early and rapid. In this context, olive factories and Christian churches
are very important in reconstructing the history of this area in northwestern Syria.
Qalb Lozeh, one of a number of well preserved old churches belonging to the Ancient Villages of Northern Syria,
is located in the middle of a Druze village on the Aʼla Mountain. Qalb Lozeh translates as "Heart of the Almond" inArabic. The elevation of the village is 670m, and it is situated about 50km west of Aleppo and 28km north of Idlib.
Tchalenko visited Qalb Lozeh church several times and believed that it dates to the 5th century based on its Basilica
architectural style, first known in Syria as the wide basilica. The site was inscribed by UNESCO as a world heritagesite in 2011 as a part of the Ancient Villages of Northern Syria.
There is debate about why the early Christians in the Levant chose Old Greek Basilica style architecture for theirchurch style. Some scholars asserted that they adopted this communal building style because it was quite different
from the Roman temple style. Other scholars thought that as many people gathered during Christian worship, theyneeded a Basilica style public building in which they could gather.
The early Christians adopted the Roman Basilica style for their churches however they build them according tocertain specifications. The churches had a relatively long east and west alignment and the domed apse was situatedat the eastern end of the nave, with a doorway at the opposite end. In Qalb Lozeh, both sides of the nave have anaisle and reflect the style of a three corridor-type basilica. Qalb Lozeh is a unique Syrian Basilica style church. It
has a flat wooden ceiling, and the structure consists of a series of cut stones. The colonnade is comprised of a prism
not a column. Therefore, the inside is similar to the hall-type cathedral, which appeared in Europe in the middle
ages. In addition the loggia at the entrance had two small towers on both sides, a characteristic of Early Syrian
church buildings. Therefore, the photogrammetry project at Qalb Lozeh is very important as it facilitatesdocumentation and preservation of typical early Syrian Church styles.

Butler, H. C. 1920 Early Churches in Syria, Fourth to Seventh Centuries, Princeton.

Callot, O. 1984 Huileries Antiques de Syrie du Nord, Bibliothèque archéologique et historique, t. 118), Paul
Geuthner, Paris.

Mattern, J. 1944

A Travers les Villes Mortes de la Haute Syrie, 2e édition. Beyrouth.

Sodini, J. P. et al. 1980 Déhés, campagnes I ‒ III (1976-1978). Recherches sur lʼhabitat rural, Syria 57: 1-308.
Tate, G. et al. 2013 Sergilla 1. Village dʼApamène. vol.1 et II, BAH.

Tchalenko, G. 1953 Villages Anitiquities de la Syrie du Nord: Le Massif de Bélus à lʼÉpoque Romaine, Paris.

Vogüé, M. de 1865-1877 Syrie Centrale, Architecture Civil et Religieuse, du 1er au Ve sicles, Paris.

3

Qalb Lozeh (General view from southeast)

Qalb Lozeh (General view from southeast)

4

Qalb Lozeh (General view from west)

Qalb Lozeh (General view from east)5

2. The process of making a 3D image of Qalb Lozeh
Sari Jammo
As a result of the chaos within the country in recent years Syriaʼs cultural heritage is facing its greatest challenge. Manyarchaeological sites were destroyed; a large number of sites withstood secret excavations and vandalism and thousandsof archaeological objects have been smuggled abroad. Under these circumstances and feeling a sense of responsibility
toward Syrian culture properties, a project to evaluate damage, safeguard and document cultural heritage sites in the
Idlib governorate was begun. The objective of the project is to provide knowledge, raise awareness and build thecapacity of local people and civil volunteers interested in and passionate about safeguarding their cultural heritage forthe future.
The first site, Qalb Lozeh was chosen for its symbolic meaning. This site is famous for its 5th century Byzantine churchand many people in Harem district are familiar with the site and consider it a magnificent building.
The team is small, comprising archaeologists, amateur photographers, students and members of the public. Some havean archaeological background but others feel a sense of shared responsibility toward heritage. The project began withavailable capabilities and simple equipment such as a camera. None of the members had any experience ofphotogrammetry in cultural heritage or 3D modeling techniques and methods.
The work necessitated acquiring the theoretical knowledge and practical skills to undertake the photography.
Theoretical aspects include providing the team with simple teaching and technical information that has beentranslated into Arabic. Even though this work does not require special knowledge in photogrammetry or measurement,
there are several tips and user techniques that could affect the end results. However, the team members were asked
to read the context carefully and understand the basic principles of photogrammetry at least. Later, an online meeting
was held via the Internet. During the meeting, a lecture explained the basic knowledge and simple steps for taking
photos suitable for creating 3D models. Necessary information related to adjusting the camera, quality of the photos,
appropriate exposure time, shadow angles, technological principles of photogrammetry, the appropriate way of taking
overlapped photographs and examples of success and failure were introduced to facilitate understanding.
The practical aspects of applying learnt theoretical knowledge in the field and taking the photographs was moredifficult than had been anticipated. Taking the photographs required keeping the learned theoretical principles inmind. The idea of taking photographs is not limited only to the whole parts of the building, but to cover it with
continuous and overlapping images. A 3D model is mainly generated from a series of photos with continuous overlap
and these photos should not be discontinuous. The photos cannot be processed well when the overlap is less than 60%.
However, the appropriate and recommended overlap of the photographs should be greater than 60%. The result of
the processing is proportional with the increase in the percentage of overlap and the opposing right side of the image(the recommended overlap is said to be 80-90%).
At the beginning of the work, a series of 150 photos were taken, but these were general photos covering the externalpart of the church building. None of the learned principles were applied and the photo series was a failure. The
7

following, attempt placed emphasis on the principles of taking appropriate photographs and considering overlap. New
sets of good photographs were received particularly for the lower levels of the church.
Difficulties and unexpected circumstances were encountered when working in the field. The ongoing security
situation did not allow the team to undertake its work easily. They had to postpone intended work for days andsometimes weeks till the security conditions improved.
Lack of appropriate equipment created other difficulties and as mentioned previously, it was decided to start with justa camera. Measuring and photographing the lower levels of the church building up to a height of five meters was
relatively easy, but photographing the higher elevation walls, arches, pillars and external side of the dome of the altar
was more difficult. To reach the higher elevation, the team had to use long poles and/or a drone. Drones are useful intaking reliable photographs, but unfortunately, in the beginning none were available. As a result members of the team,
were climbing the walls, standing on the top of the car and adjusting the focal length (zoom lens), but later problems
were encountered when processing these photos. These experiences showed it is better to use the same focal length
for the entire photo series, as using different focal lens resulted in blurred images.
Many typical mistakes occurred during taking the photographic sequences. One of these was the adjustment of thecamera direction and location. The photographer seemingly overlapped the sets of continuous photography, however,when processing the photographs in the software, the results were poor. The reason is because the photographs weretaken from one position by rotating the camera only. It is necessary to move the camera position during taking thephotographs, or change the camera angle incrementally.
It was very difficult to measure and photograph the highest points of the church especially the ceiling and the apse
dome above the altar. In order to achieve this, the team started looking for an appropriate method (using long poles,
cranes or a drone). Luckily, they found a drone in the area and asked the droneʼs owner for cooperation and help. The
team could use the drone once for 40 minutes. During this time several photos were taken and a short video wasrecorded. Unfortunately, the photos were not well overlapped and the side of the church has not been photographed.
Lack of appropriate overhead photographs may result in severe skewing and holes. Hence there were large changes inangle between the overlapping photos taken from the ground and those from the drone resulting in failure inprocessing and combining the photos.
Measuring and photographing the entire site took about a month. In total, the team took about 3000 photographs.
More photographs of missing sections are needed and the team will do their best to create a 3D model from thephotographic series. However, it is the first cultural heritage-documentation project undertaken by this group. The
measuring and photographing skills of the photographers gradually improved throughout the process of recording thechurch but further skill development is necessary. Hopefully, future projects will increase the skill level and capacityof scholars and civil organizations to safeguard Syrian cultural heritage for future generations.

8

Western facade

Main western entrance

Right side square tower (down)

Right side square tower (up)Left side square tower (down)

Left side square tower (up)Northern side facade showing two doors and northern wall arches

9Apse (exterior part)

Apse (columns and windows)

Southern side facade showing three decorative doors

First door (east)

Second door (center)

Third door (west)

View from the south west

10

The nave of the church

Rows of columns

Second arch (south)

South side aisle

South side aisle

Southeast side room entrance

Column decoration

11

North side aisle

North side wall

Apse (interior part)

Apse dome

Apse dome

Dome decoration

Clerestory

Church floor in front of the main entrance

12

3.

3D reconstruction of Qalb Lozeh
Nobuya Watanabe

1.

Background1.1.

Method and limitations

The 3D model of Qalb Lozeh illustrated in this brochure is generated by Photoscan Pro (Agisoft), the SfM software,
based on the photographs collected by local colleagues in Syria. The processing result was acceptable for obtaining
a general view of the church as shown in the following sections. However, there are still several missing sections in
the models due to the lack of photographs. In particular, orientation and continuity of the model inside the church
was distorted, probably because of the difficulty in taking appropriate sets of overlapped photographs. Thus, thefinal model was made by manually integrating several section models into one single model (Figure 1 and Figure2). Automatic alignment was attempted for integration but did not create a satisfactory result. The lack of precise
GCPs around the church may have affected the automatic integration of the model. At least, there are several known
sets of points whose length in between gives scale to the model. Also, the directions of the vertical and horizontal
axes were determined from these sets of points. The model can provide orthographic plans since the scale anddirection of the axes are known. However, it should be noted that the model might include disorientation andskewness as a result of the integration procedure. The accuracy and analysis of the missing sections is expected tobe resolved in future work when additional photographs are available.

Figure 1 Overview of the integrated model of Qalb Lozeh

13Figure 2 Separated sections of the model
1.2.

The illustrated figures

There are two sets of illustrations for most figures in the following chapters. One is a realistic 3D image and theother is a gradational colored relief model. It is easier to observe the surface using the relief model while the realistic
model confirms textures and colors. The color of the relief model shows the difference in distance between theoverlapped models (i.e. errors when integrated). The presence of more red indicates the greater the distance
between the overlap (about 9 cm in maximum).
2.

Birds eye-view of the church

A birds eye-view from several stand points are introduced in this section. The outer side of the church is comparably
well generated. However, the model lacks the roof of the apse, the top wall of the northern side, and the structures
on both sides of the main entrance. The photographs taken by the UAV1 augment the model of the roof in thesouthern section. Improvement in the photography of the higher sections of the building is required in future efforts.
1

UAV (Unmanned Aerial Vehicle) is another name for so called drone. UAV is now one of the most important

platform for taking aerial photographs, not only for just recording scenery but also for mapping purpose.
14

Figure 3 Birds eye-view from the south-west

15

Figure 4 Birds eye-view from the south

16

Figure 5 Birds eye-view from the south-east

17

Figure 6 Birds eye-view from the east

18

Figure 7 Birds eye-view from the north-east

19

Figure 8 Birds eye-view from the north20

Figure 9 Birds eye-view from the north-west

21

Figure 10 Birds eye-view from the west
3.

Sections of the church

Areas of the church are illustrated using orthorectified photographs in this section.
3.1.

Plans of outside walls

As previously stated, plans can be generated from the model taking advantage of its correct scale and orientation.
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Figure 11 Plan of the lower part of the church (north).

Figure 12 Plan of the lower part of the church (south)
3.2.

Inside walls

The walls inside the church are illustrated by slicing the model in half. One of the advantages of using this method
is that it is possible to slice and to observe any section. Consistency of the walls is acceptable in most parts of themodel. However, discontinuity with the apse is noted (Figure 13).

Figure 13 Section of the inside walls (the southern wall from the north)23

The inner side of the northern inside wall could not be processed. Thus, the section on the outer side is shown(Figure 14). The model also lacks the pillars that actually exist in situ at the site.

Figure 14 Section of the inside walls (the southern wall from the north)
The front section of the apse shows the left wall structure to be skewed, likely as a result of the reconstruction. The
right wall has duplicate errors, which occurred when integrating the models.

Figure 15 Front section of the apse (from the west)
24

3.3.

Top views and plans

The church was horizontally sliced at several heights to illustrate the top views. The floor is not shown because only
a portion of it could be generated in the model.

Figure 16 Horizontal slice near floor level.

Figure 17 Horizontal slice near the lower roof.
25

Figure 18 Horizontal slice around 3 m from the ground.
The creation of a top plan was attempted using the above figures. However, the area inside the dotted circle in
Figure 19 shows the areas which are mostly un-modeled or clearly skewed.

Figure 19 Top plan of the church

26

4.

Comparing the components

The plans (orthorectified photographs) of the components of the church are listed and compared in this section.
4.1.

Entrances

The basic square shape in the wall is common for all entrances. However, the decorations around the entrances inthe southern wall are all different while they are same in the northern wall. The biased location of the symbol (nextparagraph) in the south may imply that the south side of the church is more decorative than the north side.

(A)

(B)

(C)

(D)

27

(E)
Figure 20 Comparison of the entrances in the wall
4.2.

Masonry

Several characteristic masonries observed in the church are shown in the following figures. Again, the figures are
orthorectified.

l(A)

(B)

28

(C)

(D)

(E)

(F)

Figure 21 Masonries observed in the church
29

4.3.

Symbols

The representative symbols observed in the church are shown in the following figures. All of the listed symbols arepresent on the outer side of the southern wall. Symbols were not observed on the northern wall, or at least theycannot be known from the model.

Figure 22 The symbols observed in the church
5.

Attempt at 3D visualization

The use of a UAV will cover the dead spot in photographing. It is especially difficult to take photos of roofs and thesurrounding landscapes. Not only the structure itself but also the landscape can be quite important to give context
about the site of interest. A UAV can easily obtain this “landscape” information. However, it may not be easy to use
a UAV in some countries and areas. In this case, Google Earth is another solution for adding this kind of information.
Integration of UAV derived data and Google Earth will be introduced in this section.

30

5.1.

Model generated from the UAV

The figures here are generated from the UAV, using 4K images cropped from the movie taken by a DJI Phantom3.
The ground, the floor, and the roof are properly modeled since the camera was set to vertical. However, lack ofphotographs on the side of the walls and inside the church hinders the completion of an appropriate model.

Figure 23 Birds eye-view from the south-west (model generated from the UAV)

Figure 24 Zoom up to the church from south-west (model generated from the UAV). Part of the southern wall isbadly skewed.
The UAV derived data (floor and ground) and the result from the handheld camera (church) were combined(Figure 25). The result was mostly successful, although there were several gaps, which could not be filled. The
photography area around the church was limited because of safety reasons. Of course a UAV is capable of taking awider extent if the circumstances allow.
31

Figure 25 Combined model derived from the UAV and the hand held camera.
5.2.

Combining the model with Google Earth

The model was combined with Google Earth satellite imagery using Sketchup (Trimble) (Figure 26). The
surrounding landscape can be observed from this result. As a result, the geographical context of the church andits surrounding enironment can be understood.

Figure 26 Model combined with Google Earth satellite image

32