|A NATIONAL GEOGRAPHIC PORTAL
Haim Srebro, Jacob Bar-Lavi and Benny Weiss
Survey of Israel, Tel-Aviv
Since 16 years ago a National GIS was built by the Survey of Israel (SOI) to serve the government ministries and agencies as well as to support the community of nation-wide geospatial consumers.
The data source of the National GIS was based on triangulated aerial photographs using analytical and digital photogrammetry.
A year ago a new initiative was launched by the Survey of Israel: A National Geospatial Portal. This portal has been developed in cooperation with the Inter-agency Committee for GSDI. The prototype of the portal is already working, ready to be installed before the end of the year. It will be part of the E-Government initiative and will serve simultaneously as a geospatial portal for the public and a governmental GIS clearing house. Following a thorough analysis of the options, the decision was made to build a geospatial data warehouse at the first stage, in order to improve the quality control of data. This approach was adopted because of the variety of data sources. Though the quality of data based on the National GIS is very high, one cannot assure the quality of uncontrolled data coming from all ministries and agencies, so that integrated applications of the simple end web-user may not meet the expected standards.
In order not to loose the confidence of the public, and to improve the reliability of the portal, the warehouse approach will be followed, enabling a change in the future to a distributed approach like the one implemented by the US geospatial one-stop portal.
Following the resolution of the Inter-agency Committee with reference to the national geospatial meta-data standard, this standard was adopted for the portal as well.
Meta-data for 400 layers of geospatial data has already been prepared and is accessible in the system, which operates as of May 2006 in an intranet mode.
The system works quite fast and passed successfully loading simulations. Potential users are exposed to the portal and are very satisfied with it, including the education community and potential emergency applications.
The paper elaborates also on the technological environment and tools used for the project.
The main targets of the geospatial portal
The main target of the portal is to concentrate, to integrate and to distribute geospatial data following the e-government policy of making the data available to the public.
The second target of the portal is to serve as a clearing house of geospatial data between governmental offices and thus to save governmental investment and to improve compatibility and integrativity between governmental offices regarding geospatial and location based applications.
The expectation is that the exposure of data will also stimulate processes of improving the quality and precision of the data.
The portal is developed and managed by the Survey of Israel and coordinated with the Inter-Agency committee for geographic information.
A steering committee of the two organizations headed by the Director General of the Survey of Israel (who chairs the Inter-Agency committee) defines the goals and confirms the planning. A working team of the committee defines the requirements and controls their achievement while working teams of the Survey of Israel are responsible for their execution.
The main components of the system are: data collection, data integration, simple web operational search mechanisms, national geospatial meta-database, data sharing and data distribution mechanisms and a variety of links to GIS and mapping web sites.
The portal is planned to be installed on the central governmental web site, using its services including security of data.
The alternative strategies
The main alternative strategies that were discussed at the design stage of the portal were:
To adopt the technology and architecture of the American GOS (Geospatial One Stop), which integrates map services, which exist in various offices in the government, and extracts data using data harvesting technologies supporting the meta data of the portal.
To develop a central system which depends on distributed databases, similar to the idea of data marts which is common in the IT market. The core idea behind this alternative is that the governmental offices enable the portal direct accessibility to their data servers, and the portal engines read the data and present it.
To adopt the idea of a geospatial data warehouse (DWH) in which the data, including the metadata, is concentrated in one database using ETL tools (Extract, transform and load) for populating and periodically updating the data warehouse.
The following are the advantages and disadvantages of the different strategies:
- The technology was applied in other countries.
- The investment in development is relatively small (mainly in the Hebrew interface).
- There is a tangible application base for decision-making.
- It fits large countries such as USA, India, but doubtful for Israel.
- It depends on the existence of Map Services in the relevant organizations.
- No control on cartography.
- At time of decision making the GOS of ESRI has undergone changes.
- It is philosophically right (A distributed database).
- Governmental offices do not have to "depart" from data.
- Each office is responsible for its database maintenance. The SOI will have to invest less.
- It will be more difficult to implement comparing to DWH due to decentralization.
- Problems of coordination and communication.
- Central control of the database and high application prospects.
- Control of cartographic presentation, gathering of subjects, searching, etc.
- The variety of technologies in governmental offices is not a restriction.
- Short setting up.
- Development of complex ETL engine for loading & updating is required.
- No direct access to operational databases.
- SOI responsibility for maintenance.
- Refusal of governmental agencies to depart from their data.
- Difficulty to integrate data from local government.
Decision and concepts of implementation
For the current stage of the geospatial portal, the decision was to adopt the Data Warehouse concept. The main reason for it was that the process could be better controlled, since an initial validation could be made for data, which is imported from various sources. Thus, not loosing the credibility of the project at the first stage of the portal, when gaining the confidence of the users is crucial. In addition the core of the portal, which is the data of the National GIS of the Survey of Israel, already exists and easily accessible since the project leader is the Survey of Israel. In addition, Israel is a small country and the access to the data covering the whole country in various governmental agencies is relatively easy.
Additional resolutions were accepted with regards to the geographic portal:
To adopt a simple system for the integration of the presentations of geospatial data and geospatial data keys. This was accepted due to the decision to begin first with free access of the public and then to develop the intranet between the governmental offices.
To implement the concept of openness and transparency of the GIS, for the presentation of a large scale of geospatial data layers free of charge to the public.
To concentrate and manage the geospatial meta data in one organization (the Survey of Israel), implementing a national meta data standard based on ISO.
To make use of GIS technologies which already exist in the Survey of Israel (Using ArcIMS as the map engine, and SDE above the Oracle database).
These resolutions together with the understanding of the initial internet users lead to the following guiding concepts:
Simplicity of use – intuitive operation of the user interface both for presentation of geospatial data, and for meta data queries and presentation.
Attractiveness – clear and convenient user interface and an attractive cartographic design.
Solidity of focusing on applications.
Internal standardization – so that the user will feel familiar in any future environment which will be based on the portal.
External standardization – following Windows and Internet standards as well as Governmental standards.
Protection and license management – including dynamic management of permissions according to the application of the user.
Data included in the portal
The portal includes about 100 layers of national geospatial data from its early stage of operation, i.e. main GIS layers that are stored in various governmental offices.
The Portal represents data with great variability and richness that enable the system to sort the layers under main topics and the user to extract relevant meta data.
The portal is integrative and the data includes many topics, such as basic mapping (roads, buildings, addresses, orthophoto, contours, hydrology, institutes, various scales of raster topographic layers etc.), layers of cadastre and planning (blocks, plots, town plans, master plans, land reserves, etc.), tourist information (national resorts, national parks, hiking trails, forests, woods, parking areas, etc.), administrative boundaries, transportation, infrastructure, security and national emergencies.
The portal enables simultaneous presentation of multiple layers of information, with high cartographic fit, linked to attributed information in various formats according to the spatial entities.
In addition, and based on the general data in the system, there are engines that enable links to other databases, that might give specific information in special operative applications in the future, for internal governmental usage.
The functionality of the portal
As mention above, the portal's concept is to enable its operation by any user, professional, or random, from various disciplines. With this principle in mind the tools are divided into two sets: standard tools, which are presented on the main screen, and advanced tools that are not presented to unskilled users.
A summary description of the tools available in the portal:
Ability to present layers of data in any scale on a national map by using the function of highlighting the layers, and focusing on an area for increasing/decreasing the scale.
Ability to describe data on each item on the map, according to the information that is linked to the geospatial entities.
Easy to use search engine: by name of place, by address (street name and building number), by block and parcel number, town plan, master plan, names of public institutions and sites, road number, intersection, national resorts, national parks, coordinates (central point with radius, window, or polygon), and general string in all tables of data in the system.
Search engine to locate block/parcel according to address and vice versa.
A special engine to locate a desirable layer.
Dynamic presentation of the legend.
Printing maps in any chosen scale.
Producing general data reports.
Measuring distances and areas on maps.
Tools for integrated cross-layers geographical applications.
A choice of using geographic or SQL (dynamic queries generator) tools for map and A/N data presentations.
Copy a map (as a picture) and alphanumeric data from the system to Office documents.
"My map" – a tool to save and send by E-mail all the maps produced in a job sequence.
Search engine for meta data and their representation in tables either as a summary, or as a detailed report.
In addition, the portal includes an external interface for other operation systems (general and flexible API with parameters). The interface will have hierarchy tools in order to establish a preferable job and a manual with examples for the use of API operation.
The system architecture
Data from Government
The meta data component in the geospatial portal
The meta data is an important component in the geographical portal.
The development of the portal is progressing in accordance with the ripening of the Israeli national geographic meta data standard, as components of the National GIS standards. These processes are taking place in SOI as part of the operation of the Inter-agency Committee for GIS. The new meta data standard was approved by the representatives of the public bodies and the governmental offices, which are members in the committee, and adopted by the committee.
The development of the meta data component is based on ISO 19115, and was constructed in a way that will enable its direct feeding to ARC CATALOG (An ESRI product), but will be observed (in Hebrew) similarly to other portal components on commonly used web computers/terminals.
The meta data of the portal component is derived from the new standard, and its data structure is characterized by few and simple fields.
The meta data component matches the two basic principles of the portal: centralization of the information in a data warehouse structure, and simple intuitive operation of its visible parts.
Centralization of information in D.W.H.
Both the portal and the meta data follow the concept of D.W.H. that easing the process of data feeding and strengthening uniformity of data originating from diverse sources.
Simplicity in retrieving meta data.
The presentation of data on the information contained in the geographical portal is intuitive and simple to operate for any Internet user, including those that are not experts in geographic sites. The retrieval of data is possible in several options: by coordinates; by definition of key words; by category selection (choosing a subject of a scroll table).
All the information in the portal is accessible to the public, with no limitation or a need of passwords or permits. The meta data of the portal includes around 400 layers of GIS of countrywide coverage, or of national interest, in spite of the fact that the information included in the portal includes only a quarter of these layers. The rest of the layers are not ready for presentation for various reasons: security, intellectual property, privacy and lack of updated data.
The meta data is delivered to the public in two levels of detailing:
A centralized table: including details on each layer with regard to its contents, to ownership, and to presentation in the Portal.
Details of the meta data about the layer, its producer and the owner of the data, its accuracy level and updating, a sample data and address for communication including via e-mail.
Cooperation with the education community
We see the education community, including school pupils and university students of geography, as an important potential promising community of users. Therefore, we cooperate now with the academic staff as well as the committee for geographic education, in order to get their focused responses to be integrated and implemented in the system. On the other hand, the main goal of the cooperation is to integrate the use of the portal by the pupils and students in their geography classrooms.
This project is considered to be today our most promising one with regard to the national geospatial database and the more we advance the greater are the expectations for the benefit of the public.
The requirements of the board of education for the portal in order to fully integrate it in the learning program are very demanding and can not be met for the initial launching stage of the portal. They will be taken care of on the long run. For the first stage the portal will take care of basic geographical education applications.
Examples of the methodical subjects which were required by the education committee included regional and urban geography, economical aspects, transportation, social geography, etc.
The thematic categories of the portal which may support the requirements include: basic maps, geopolitical expressions including boundaries, landscape, land forms, climate, population, settlements, infrastructure, environmental aspects, nature hazards, etc. The targets of the "learning geography package" is to teach the use of GIS tools and to stimulate the interest of students in geography.
After 16 years of building a national geospatial database, the Survey of Israel is leading a new initiative of a national geospatial portal.
This portal is constructed in coordination with the Inter-Agency committee for GIS. The data is imported from many government and public organizations to a data Warehouse. The system has been developed using client/server technology in a web environment on the basis of the shelf software (ESRI 's ArcIMS). The application is easy to operate and aimed at first stage to non GIS experts, though maintaining more advanced geographic analysis tools to be used by experts. The application can be installed at no cost on any web terminal computer. In addition to serving the public the portal will serve in the future as a geospatial clearing house in the government. The exposure of the system to the public is scheduled before the end of the year.