have become available. However, the quality of scanned declassified analogue
image data is not very high for some early-date images, such as the Multispectral
Scanner (MSS) images from the first Landsat (see Fig. 3.4).
Satellite images from 1968, 1973, 1975 and 1980 were used (see Figs. 3.4
and 3.5). These declassified satellite images are freely available from http://
edcsns17.cr.usgs.gov/EarthExplorer/). The Corona satellite system (KeyHole-4B)
represents many types of satellites and cameras. The image from 1968 was taken on
16.8. using AFT 70 mm stereo high-resolution camera on black and white film and its
quality is very good. Images from other years (1980-07-07, 1975-06-19, 1973-12-23)
were taken using KeyHole-9 on 9 Â 18 in. black and white film with theoretical
resolution of about 6–9 m and they quality is worse.
For our work, it was necessary to search through hundreds of images on the
USGS server and find suitable data. From selected images it was necessary to create
cuts within a relevant area of the Erbil city. The next step was to logically enhance
the images (filtration, interpolating, etc.); the quality of scanned analogue film data
was in many cases not very high. After this, cuts were transformed to control points
and processed to the vector data.
Fig. 3.3 An oblique aerial photo of the Citadel in 1933 (Erbil archive)
46
K. Pavelka and E. Matous ˇkova ´
image data is not very high for some early-date images, such as the Multispectral
Scanner (MSS) images from the first Landsat (see Fig. 3.4).
Satellite images from 1968, 1973, 1975 and 1980 were used (see Figs. 3.4
and 3.5). These declassified satellite images are freely available from http://
edcsns17.cr.usgs.gov/EarthExplorer/). The Corona satellite system (KeyHole-4B)
represents many types of satellites and cameras. The image from 1968 was taken on
16.8. using AFT 70 mm stereo high-resolution camera on black and white film and its
quality is very good. Images from other years (1980-07-07, 1975-06-19, 1973-12-23)
were taken using KeyHole-9 on 9 Â 18 in. black and white film with theoretical
resolution of about 6–9 m and they quality is worse.
For our work, it was necessary to search through hundreds of images on the
USGS server and find suitable data. From selected images it was necessary to create
cuts within a relevant area of the Erbil city. The next step was to logically enhance
the images (filtration, interpolating, etc.); the quality of scanned analogue film data
was in many cases not very high. After this, cuts were transformed to control points
and processed to the vector data.
Fig. 3.3 An oblique aerial photo of the Citadel in 1933 (Erbil archive)
46
K. Pavelka and E. Matous ˇkova ´