satellite images. Long-term trends in built-up areas are clearly visible. In the longterm proportions urban areas, roads, housing and industrial estates enlarges. To
obtain the most reliable results it would be necessary to ensure the scanned
negatives of photos and to determine internal orientation parameters of the used
camera together with other supporting data like an approximate image scale, the
exact date, etc. If possible, it would be convenient to create orthophotos from either
a stereo image pair or from photogrammetric images and sufficiently accurate
digital terrain model. Digital terrain models can be obtained from photogrammetric
processing or the digitized contour lines from maps can be used; recently airborne
laser scanning can be employed. The archived maps are suitable to data set
complement. They often describe interpreted components the best and they allow
one to obtain appropriate control points. The transformation of historical maps is a
separate issue (Cajthaml 2013; Krejc ˇı ´ and Cajthaml 2009). In some cases they are
available only in a form of sketches that are low or locally different positional
accuracy.
The turn of the twenty-first century brought rapid development in satellite and
aerial image technology together with data processing. A number of various
innovations had been made. There is the utilization of airborne laser scanning for
3D city model creation. Satellite images with geometrical resolution better than 1 m
in panchromatic range and with a resolution of 2–4 m in multispectral range are
available. Precise GNSS instruments are at our disposal. This considerably
increases accuracy and possibilities available when applying classification
methods. Given the tumultuous growth and development of settlements in many
places on the world together with accumulation of people in megacities, such data is
extremely valuable. If one wants a longer look to the past, a necessary compromise
on details and on existing data quality must be made.
In our case study, increasing or decreasing areas of classes, for example in
graphs or tables, can be seen (based on differences in the sum of individual classes
given by an interpretative key). In many cities the development of industrial areas
can be observed with a peak in the 1960s and after the year 2000, always accompanied by a certain kind of housing construction. Transport infrastructure often
tends to delay significant changes from occurring in the construction of airports and
motorway junctions. On the contrary, the railway did not develop as rapidly as in
the last century (only high-speed tracks in Europe, Japan or China). A clear trend is
the migration of people to big cities in the 1980s, which still continues. In many
cases on the earth, this leads to uncontrolled expansion, which is very hard to
handle. This rapid expansion can be only observed or, with certain difficulties,
predicted. This allows us to perform timely interventions. However, it is possible to
successfully document the development and direction of the city growth through
the above-mentioned technology. It is necessary for planning and especially for the
sustainable development of the area.
The virtual model of the Al Qala Citadel has been created. The analysis of the
model quality assessed the precision of the model and showed ways of precision
improvements, which were realized. The field calibration of aerial and terrestrial
image sets was very important. It has improved the project precision and, at the
58
K. Pavelka and E. Matous ˇkova ´
obtain the most reliable results it would be necessary to ensure the scanned
negatives of photos and to determine internal orientation parameters of the used
camera together with other supporting data like an approximate image scale, the
exact date, etc. If possible, it would be convenient to create orthophotos from either
a stereo image pair or from photogrammetric images and sufficiently accurate
digital terrain model. Digital terrain models can be obtained from photogrammetric
processing or the digitized contour lines from maps can be used; recently airborne
laser scanning can be employed. The archived maps are suitable to data set
complement. They often describe interpreted components the best and they allow
one to obtain appropriate control points. The transformation of historical maps is a
separate issue (Cajthaml 2013; Krejc ˇı ´ and Cajthaml 2009). In some cases they are
available only in a form of sketches that are low or locally different positional
accuracy.
The turn of the twenty-first century brought rapid development in satellite and
aerial image technology together with data processing. A number of various
innovations had been made. There is the utilization of airborne laser scanning for
3D city model creation. Satellite images with geometrical resolution better than 1 m
in panchromatic range and with a resolution of 2–4 m in multispectral range are
available. Precise GNSS instruments are at our disposal. This considerably
increases accuracy and possibilities available when applying classification
methods. Given the tumultuous growth and development of settlements in many
places on the world together with accumulation of people in megacities, such data is
extremely valuable. If one wants a longer look to the past, a necessary compromise
on details and on existing data quality must be made.
In our case study, increasing or decreasing areas of classes, for example in
graphs or tables, can be seen (based on differences in the sum of individual classes
given by an interpretative key). In many cities the development of industrial areas
can be observed with a peak in the 1960s and after the year 2000, always accompanied by a certain kind of housing construction. Transport infrastructure often
tends to delay significant changes from occurring in the construction of airports and
motorway junctions. On the contrary, the railway did not develop as rapidly as in
the last century (only high-speed tracks in Europe, Japan or China). A clear trend is
the migration of people to big cities in the 1980s, which still continues. In many
cases on the earth, this leads to uncontrolled expansion, which is very hard to
handle. This rapid expansion can be only observed or, with certain difficulties,
predicted. This allows us to perform timely interventions. However, it is possible to
successfully document the development and direction of the city growth through
the above-mentioned technology. It is necessary for planning and especially for the
sustainable development of the area.
The virtual model of the Al Qala Citadel has been created. The analysis of the
model quality assessed the precision of the model and showed ways of precision
improvements, which were realized. The field calibration of aerial and terrestrial
image sets was very important. It has improved the project precision and, at the
58
K. Pavelka and E. Matous ˇkova ´