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International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Vol XXXV, Part B6. Istanbul 2004
maps and spatial data. In case of allocating proper budget to
this project, it is planned to finish the production phase of
theses data within 5 years. Obviously the updating process
has to be started during this period.
3.3 Image Maps and Digital Elevation Models
In the past, photo maps were produced using conventional
aerial photography and analogue photo rectification techniques
in a limited number in NCC. During the last few years, there
has been a revolutionary increase in demand for different types
of image maps in Iran, thanks to accessibility if high resolution
remotely sensed data, proper software systems and very fast
computers.
During last year, 20 large and medium scale image mapping
project have been performed by NCC which shows a growth
rate of 4 proportional to the year 2002. It is planned to develop
the role of private sector in image map production by increasing
the users request for these products.
In order to promote remote sensing activities in Iran, NCC
decided to facilitate accessibility of users to geo-referenced and
geometrically corrected image data. For this purpose a pilot
project was executed with a full coverage of Landsat ETM"
imageries for whole country which goes through a rectification
process using 1:25000 base maps and 10m DEM of Iran. The
final product of this project will be presented as ortho-rectified
14m PAN and 28.5m multispectral satellite imageries in a block
wise manner. Note that the country has been divided to about
132 blocks with dimension of 1.5 degree in longitude and |
degree in latitude. This product can also be used as background
of 1:250000 scale maps of Iran. By now, 40 percent of this
project has been finished.
Digital Elevation Model is another key element of every image
mapping and remote sensing activity. In response to this need,
in 1997, NCC has produced and presented a DEM of entire
country with resolution of 25 arc second. The source data for
this product was digitized 1:250000 paper maps. Another DEM
data with 100m resolution was created in 2000 by Iranian
Remote Sensing Center using the same data source.
In 2001, NCC decided to produce a national DEM from
1:25000 base map series with 10m resolution. At present, 60
percent of the country is covered by these DEM data with
height accuracy of better than 6 meter.
3.4 Cadastral Activities
In 1995, due to lack of a comprehensive and effective cadastral
system, the government decided to execute a cadastral project
under supervision of land registration office of Iranian
judiciary. The planned cadastral system was based on cadastral
maps with scale of 1:500 to 1:1000 for urban areas and 1:1000
to 1:2000 for rural arcas. As mentioned before, in order to
increase the speed of this project, an agreement has been made
to use the 1:2000 digital maps of cities in combination with
additional field works for this purpose.
Beside this national project, a number of rural cadastral projects
are carrying on every year by private companies according to
different contracts. One of the biggest cadastral projects in this
group was executed during last two years in response to request
of Gilan provincial water authorities in northern Iran. For the
first time in the country, a combination of topographic maps,
orthorectified images as base data and extensive field work
were used in order to perform a cadastral project. This project
covers an area of 1000 km? and costs about 1.4 million US
dollars.
4. METHODS AND TECHNOLOGY
4.1 Data Production Policy
Until recent years, the only comprehensive program for map
and spatial data production in the country was limited to
1:25000 base maps and associated data bases. In this
atmosphere, the situation of private sector could not be so good
since their customers were a limited number of governmental
constructive project owners. Lots of efforts have been made
during these years to introduce capabilities of digital maps and
geographic information systems to actual and potential users
with this idea that the interaction with user community implies
that they should determine the usefulness of the data and
system. These efforts resulted in establishment National
Council of GIS users by NCC to collect their needs and to
interact with them. Preparation of the above mentioned strategic
plan and approval of national mapping projects such as
completion and updating large scale digital maps of cities with
an estimation of 50 million US dollar cost can be considered as
results of these activities.
These medium term plans for mapping with direct support of
the government culminated in a rapid development of private
sectors and we witness increasing amount of governmental
contract with private companies during the recent years. The
following table shows the number and amount of
photogrammetric digital mapping contracts with private
companies during the past four years:
Year Number of Contracts Total Amount in US$
2000 53 1 100 000
2001 77 1 980 000
2002 105 3 750 000
2003 145 5 330 000
4.2 Photogrammetric Digital Mapping Systems
Digital map production has been started in Iran since 1995 by
upgrading analogue stereo plotters of NCC and the upgrading
program was so successful that within less than 5 years, all the
photogrammetric systems in the country were upgraded.
Nowadays, the number of digital photogrammetric workstations
in the country have increasingly grew so that reported sold
systems of Iranian Paradyes'" photogrammetric workstation
passed the number of 200. Note that just 25 of these systems are
installed in NCC.
In order to show the acceptance of digital photogrammetric
systems in the country, the number of scanned aerial
photographs can be considered as another measure. The
following table shows this figure during the period of 2000 to
2003:
Year Number of Scanned Photos
2000 8300
2001 12800
2002 21200
2003 33000
