| National GIS Meets Demand for Maps
Quality of the maps produced exceed old manually produced maps
By Laura Maron The Survey of Israel (SOI), founded in 1920 by the British authorities as the Survey of Palestine, is responsible for the geodetic infrastructure of Israel, including its geodetic control network, national cadastral, and topographic mapping. It provides the mapping infrastructure for both military and civilian geographic information systems.
The current topographic 1:50,000 map coverage of the state of Israel is based on an old photogrammetric base that was created during the 1950's. In fact, the country's geodetic infrastructure, or triangulation network, was based on data collected by the British until very recently. Israel's photogrammetric base has been undergoing a series of changes and updates from various sources, leading to the currently inaccurate and partially-updated map coverage.
Driving these changes and updates are a number of political and economic factors. Diplomatic negotiations have resulted in frequent changes to Israel's borders with Jordan, Egypt and the Palestinian National Authority. These diplomatic processes, combined with an enormous influx of immigrants from the former USSR and an economic boom that brought about the need for new roads, cities and other infrastructure elements, has created an increased demand for updated maps at a scale of 1:25,000 and up.
"Israel is a country with an exceptional demand for maps. We print some 8 million maps yearly, similar to the large and developed European countries," said Giora Golod, deputy director, Survey of Israel, Information and Mapping. Remember, these 8 million maps are created for a country with only 80 map sheets at a scale of 1:50,000 - about 25,000 square kilometers.
Therefore, a decision to create a new topographic coverage at the scale of 1:25,000 was made. This new coverage is being built into a new national geographic information system (GIS). New printed map series would then be produced directly from the GIS, using automated cartography procedures running on top of MicroStation.
However, creating a national GIS is a long-term process. And creating quality maps out of this GIS is another major task that consumes considerable resources and time. All these obstacles could result in an unacceptable delay in the flow of updated maps, many of which are critical to the fragile peace process in the region.
It was made clear that the updated map flow could not be suspended for such a long period of time. A solution that would allow a smooth transition from the old map updating method to the new one was required.
In order to solve this problem, the SOI needed to automate the existing updating process for maps in such a way that each stage within the map reproduction workflow could be done independently, then smoothly merged into the existing manual processes. This way, system continuity would be maintained while an increase in existing throughput would be achieved from day one.
To develop its new system, the SOI turned to Advanced Technology LTD. ATL is Israel's biggest system integrator and Bentley's GeoSource provider in the region, with a long and proven history of expertise in digital cartography, digital photogrammetry and in building national mapping and geographic information systems based on MicroStation.
"In a working production environment like the Survey of Israel, operational considerations are critical for system success. A demanding customer like the Survey of Israel expects to have immediate improvements from day one, and that's what we have achieved here," said Michael Arieli, ATL's Bentley products manager and CMUS project manager.
The Survey of Israel had very specific requirements for its new system. The system had to be able to meet its existing workflow, and the same personnel who were currently doing the manual cartographic and reprographics editing had to be able to use the new system. In addition, the same data sources used within the current workflow would also be used by the new system; the same printing procedures will be used to print the new maps. And finally, the maps produced by the new system had to have exactly the same 'look' as the old maps.
The new system was developed on top of MicroStation Descartes and MicroStation GeoGraphics. It controls the processing workflow, and provides special tools to define SOI's specific features and symbology. The system also provides easy-to-use updating and editing tools and seamless multi-layered raster maps management system. Special set-up and resource files were built to define Survey of Israel's custom symbols, custom lines, patterns and rasterization parameters.
With its new system, the first step in SOI's workflow is to scan the existing map separations in high resolution. Registration (geocoding) of all map separations and the updates source to each other and to Israel's national grid is the next step. Then all the map layers/separations (6-8 separations per map) are displayed. Each layer is displayed while respecting the exact printing color in the right order and transparency, to provide the look of a final, printed map.
Heads-up digitizing or vectorizing of the updates from the update source occurs next, with each update digitized with the appropriate feature code to define the right symbology. The imported updates from digital sources are then resymbolized to have the appropriate symbology.
Smart rasterization of the new vector data into the appropriate map separation raster file is next. The vector data is automatically rasterized to the relevant layer/s (in the case of a dual color feature like a road), and then raster editing of the updated raster separations takes place.
After quality control procedures, the final film is printed, new printing plates are prepared, and a final digital raster map for the raster map archive (low and high resolution) is produced.
"Changing our international borders with Jordan and the changing borders with the Palestinian National Authority should be published immediately, and cannot wait till the GIS will be completed" said Shmuel Reuveni, director of the SOI's cartography department. "This system allows us to take full advantage of the new GIS technology while maintaining and utilizing all the work and products made with the existing map printing technology."
The new system became operational within 2 months. The Survey of Israel is now expanding the system to handle the 1:100,000 map series, as well as the 1:50,000 map series. These two series are commonly used by the country's city planners, its army, and other government officials. These series must be updated first, before the SOI can present these agencies with its completely new digitally based series, which is built at a scale of 1:25,000. The new system is ideal for maintaining an updated map series and can efficiently serve as an important component in building a GIS and digital cartography system.
The cartographic quality of the maps produced by the Computerized Map Updating System equals or exceeds the quality of the old manually produced maps. Israel's old maps, based on aerial photographs and other data collected by the British more than 70 years ago, were state-of-the-art for their time, but had become extremely outdated as time wore on.
The integration of the new digitized updates with the old data is smooth and unnoticed. An SOI computer operator can fix some old problems, which can be easily seen due to the digital magnification and editing capabilities of the system. The resultant updated high-resolution seamless coverage of the 1:50,000 enables the Survey of Israel to produce new maps with different map boundaries and layers, including innovative mixed products of map layers, orthophoto and other data types.
"The level of customization that was done by ATL is a key factor in the system success," said Izi Peled, head of SOI's digital cartography department. "The fact the operator is doing the same things he would do with the manual system but with computerized tools, and the immediate WYSIWYG (What You See Is What You Get) display of the updates have contributed to the high motivation of the operators to move into this new system."
This seamless 1:50,000 high-resolution raster map coverage will be one layer of the country's imagery database. The next obvious layers will be the 1:100,000 map coverage and the seamless orthophoto coverage currently being built by the Survey of Israel and ATL's subsidiary ADM (Advanced Digital Mapping). Currently, the raster files are stored on the SOI file server while the management data is stored in the SOI central Oracle database. According to Giora Golod, deputy director, the SOI plans to store all spatial data, including the imagery in their central Oracle database. They are currently testing this database with Bentley's ModelServer products.
The changes to Israel's base maps are part of larger, sweeping changes occurring in the country. For its first 50 years, Israel's main focus was on defense; infrastructure issues and the mapping needs they represent, when weighed against issues of national security, were postponed or ignored.
Now, as Israel prepares to meet the challenges of a burgeoning population and the necessity of competing in a global economy, the issues that were long put on the back burner are moving to the fore. A new Cross-Israel highway is planned, along with major upgrades to the country's Ben Gurion Airport and even a mass transit system to serve Tel Aviv and its suburbs. To accomplish all of its planned improvements, Israel will need flexible, consistent, and highly accurate map coverage of the entire country - coverage the SOI is now well-equipped to provide. About the Author:
Laura Maron is corporate editorial manager for Bentley Systems Incorporated. Back |
