Article April 1999.

Mapping in Iran.

A High Priority for Sustainable Development

Iran is engaged in a huge re-mapping programme and is devoting large financial and human resources to this project. Prior to the Revolution of 1978 that resulted in the overthrow of the Shah, Iran had been mapped at small (1:50.000 and 1:250,000) scales to a reasonable standard with the help of American mapping agencies. However, immediately after the Revolution came the brutal eight year war with Iraq. These traumatic events have been accompanied by sweeping political changes; the doubling of Iran's population to 70 million over the last 20 years; and substantial economic growth in recent years.

By Prof. Gordon Petrie

The result of all these developments have been vast changes in the rural landscape, while, at the same time, the cities of Iran have expanded greatly. The old topographic maps are now largely out-of-date and no longer give a correct or complete picture of substantial parts of the landscape. In order to rectify this situation, a number of programmes have been set in motion that, in total, amount to a complete re-mapping of the country. The information given below has been acquired by the author during a week's visit to Iran made in August 1998, when he had the opportunity to visit each of the agencies concerned.

 

National Cartographic Centre

The National Cartographic Centre (NCC) is the main civilian topographic mapping organisation - though its activities are supplemented by those of the National Geographic Organisation (NGO) which is responsible for derived mapping at 1:250,000 and smaller scales. NCC has a comparatively long history, an experienced staff, well-established facilities and a comparatively large production capacity. Currently its main mission is to carry out the new topographic mapping of almost the whole of Iran at 1:25,000 scale - only the large uninhabited areas of desert in Eastern Iran (- the Dasht-e Kavir and Dasht-e Lut -) will be mapped at 1:50,000 scale. Given the size of the country (1,650,000 sq. km.), this is an enormous task to undertake.

-Aerial Photography

The basis of the new mapping is, of course, aerial photography, for which purpose, NCC deploys a fleet of four Dornier propeller driven aircraft and a single Falcon jet aircraft. These are mainly equipped with Wild RC10 and RC20 cameras, together with a single Zeiss RMK-TOP. For mapping at 1:25,000 scale, the photographs are taken at 1:40,000 scale. NCC also takes larger-scale aerial photography for use by other agencies and has extensive facilities both for film processing and for the production and supply of photographic products to a wide range of customers.

-Photogrammetry

The data acquisition for the new 1:25,000 scale mapping is carried out on a variety of analogue, analytical and digital stereo-plotting instruments. These include numerous Wild (A7, A8, A10 and B8) analogue instruments equipped with encoders and utilizing the ISM data collection software from Canada. There are also some new Leica SD2000 analytical plotters and a single Zeiss Planicomp that are employed in map compilation together with an older Kern DSR14 that is used for aerial triangulation in conjunction with locally produced block adjustment software. The map production rate needed for the huge 1:25,000 scale programme has been increased through the implementation of three shift working. This keeps the instruments busy 18 hours per day, six days per week.

-Digital Photogrammetry

With regard to the use of DPWs, since the American embargo has cut off many of the main sources of supply of these instruments, a DPW design has been developed locally. This began as a project at K.N. Toosi University and was then developed further at the NCC itself by a group of researchers including photogrammetrists, computer scientists and electronic engineers. It is now being introduced into NCC's production stream. In appearance, it is similar to that of the DVP from Canada, using a single monitor with split-screen display and the same viewing stereoscope as that used on the DVP.

-Digital Data Manipulation

Besides the photographic and photogrammetric departments, there are several sections devoted to the checking, editing and structuring of the captured photogrammetric data and to the addition of the attribute data acquired from field completion and other sources - mainly using MicroStation. The edited data is used both for cartographic production purposes internally and for the supply of structured spatial data to those government ministries and agencies that utilize CAD and GIS systems.

-Other Tasks

NCC is also responsible for Iran's hydrographic surveying and charting programme and the production of the National Atlas of Iran besides carrying out its own in-house training programme and its publishing and R & D activities.

 

Cadastral Survey of Iran

The Cadastral Survey of Iran, a quite separate organisation, forms part of the country's Land Registry which in turn comes under the country's Judiciary. The Cadastral Survey is also engaged in an enormous mapping task - that of producing new cadastral maps for the whole of Iran. Obviously this will take many years and will need very large resources for its successful completion - a staff of 6,500 personnel is planned eventually. The programme has begun in brisk fashion with the mapping of the cities of Tehran and Ahwaz and the island of Qeshm in the Persian Gulf (which is a duty-free zone). As at NCC, there is an air of great activity.

-Photogrammetric Department

A very considerable production capacity has been installed in recent years, including several analytical plotters from Leica and Zeiss using the PRO600 and R-CAP software packages respectively. Also there is a single Zeiss Phodis DPW. Once again these instruments are all being used to the maximum extent through three shift working. At present, NCC takes the required aerial photography - at 1:6,000 scale for mapping at 1:2,000 scale and 1:3,000 for the mapping of city centres at 1:500 scale. As at NCC, large numbers of personnel are devoted to the checking, editing and structuring of the digital data, again mainly using MicroStation. However the attribute data needed for land registration is much more extensive, being acquired both from field completion and from the deeds covering land and property transactions that are held by the Land Registry. This information is loaded into tables within an Oracle database.

-Field Survey Department

For the extensive survey work carried out for control purposes, field completion and the verification of property boundaries, the organisation employs a large number of land surveyors. GPS is used extensively, mainly utilizing receivers from European suppliers (Leica, Geotronics and Sercel). Total stations and EDM traversing are still employed widely in those densely packed urban areas where it is not really practicable to use GPS.

 

Tehran GIS Centre

The Tehran GIS Centre (TGIC) is an entirely separate organisation from the NCC and the Cadastral Survey that forms part of the Tehran Municipality. It supplies maps and digital cartographic data to other departments of the Municipality and to the electricity utility supplying Tehran. The city now covers 1,200 sq. km. and has a population of over 7 million people with more than 1.5 million individual properties. In this context, the collection of municipal tax revenues has been a major incentive for the funding of the programme of new mapping of the city that is now under way. The previous maps were 30 years old and badly out-of-date, not having been revised during the interim period.

-Map Production

Once again, the aerial photography is taken by NCC. However the Centre has no in-house photogrammetric capability so the photogrammetric work is undertaken by private survey companies. These mainly use AutoCAD for their drafting and editing work and submit their measured and edited data to TGIC on CD-ROM in DWG format. The graphical vector data is then structured and put into sheet form. Over 600 sheets at 1:2,000 scale have been produced so far with each sheet 1.2 x 1.6m in size. This graphical editing within TGIC is carried out mainly using PC Arc/Info and ArcView. The attribute data that has been collected in the field is loaded into an Informix relational DBMS. However most of the user departments within the Municipality tend to utilize the map data within a CAD environment using AutoCAD rather than a true GIS environment.

 

Iranian Remote Sensing Centre

The Iranian Remote Sensing Centre (IRSC) comes under the Ministry of Posts and Telecommunications and is housed in a striking new building on the west side of Tehran.

-AVHRR Receiving Station

At the top of the building is the receiving station and its accompanying processing facilities. These have been designed, built and installed by Dr. P. Baylis of the University of Dundee in Scotland. This station mainly takes down and processes AVHRR imagery from the NOAA satellites on a routine basis four times per day. Since the Meteorological Service also takes down this type of image data, the emphasis at IRSC is on non-meteorological applications. These include the generation of NVDI images to show vegetation changes on a macro scale across the country; the monitoring of sea surface temperatures in the Persian Gulf and Caspian Sea; the early warning of floods; and the monitoring of the changing areas of large lakes in Central Iran due to drought and heavy rains.

-Major Receiving Station

The IRSC also has a second larger receiving station at a location 1 hours away by road travel to the west of Tehran. This had originally been constructed towards the end of the 1970s to take down Landsat imagery. However it had not been made fully operational when the Revolution took place - since when, it has lain disused. Now plans are being made to refurbish the station and make it operational with the help of the Antrix Corporation, the commercial arm of the Indian Space Research Organisation (ISRO). A provisional agreement has been reached regarding the work but it still awaits funding from the Iranian government for its actual implementation.

-Image Processing

The Centre also carries out conventional image processing, classification and interpretation of Landsat TM imagery for geological, vegetation, soils and other thematic applications for various government ministries and agencies. However a most interesting project that is currently being discussed is the proposal for IRSC to carry out the orthoimage mapping of the huge salt deserts of Dasht-e Kavir and Dasht-e Lut - from satellite imagery on behalf of NCC using either SPOT or IRS-1C imagery. The IRS coverage will become available for the whole of Iran from the newly established ground receiving station of Dubai Space Imaging (DSI) in the U.A.E.

 

Summary

Overall the impression given to the author was one of great activity, considerable technical competence and the use of modern mapping methods and technology in spite of the difficulties caused by the American embargo. While a number of the more senior staff have been educated abroad, e.g. at the ITC in the Netherlands, there are also many well trained staff who are the products of the surveying engineering departments of the University of Tehran and K.N. Toosi University of Technology and from mapping science programmes at the Universities of Isfahan and Tabriz. Currently the Iranian mapping scene is very lively and those involved in tackling the huge task of re-mapping the country appear to have the strong support of the present government that obviously believes that the programme must have a high priority in the country's sustainable development.

Professor Gordon Petrie, Department of Geography and Topographic Science, University of Glasgow, Glasgow, G12 8QQ, Scotland, UK.

University of Glasgow