Policy issues related to maps, surveys and data sharing

Policy issues related to maps, surveys and data sharing

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B J P Mendis
B J P Mendis
Surveyor General
Survey Department, Sri Lanka
[email protected]

Sri Lanka has certain rules and regulations governing the reproduction of geo-spatial data obtained by the Survey Department. It says permission should be obtained by paying royalty calculated based on the area covered and the number of copies reproduced

The Survey Department being the national survey and mapping organization in Sri Lanka has produced national topographic base maps for the whole country on the scales of 1inch : 1 mile, 1: 250,000, and 1: 50,000, and some 50% of the country is covered with 1: 10,000 topographic data and data for the rest is being compiled using aerial photographs. Certain selected urban areas have also been covered with 1: 5,000 scale data, whereas the Colombo metropolitan area is covered with 1: 1000 scale data. Sri Lanka has commenced digital data compilation by photogrammetric methods in 1992, and commenced digitizing topographic maps in the late 1990s. By now, Sri Lanka has completed digitizing 1:250,000 scale map and 1:50,000 topographic map series, and 1:10,000 series is in progress. With these data, it has established digital topographic vector databases for GIS applications.

Any Geo-spatial dataset should be based on a proper and accurate Geodetic Control Network, which means data used by all the organizations and professionals is based on same coordinate system, same Geodetic Datum, same reference ellipsoid, and same projection system. The Survey Department has upgraded its Geodetic Control Network with the use of precise Global Positioning System (GPS) equipment, so that the Control Network is accurate enough to any kind of GIS application that can be thought of.

Policy
Geo-spatial data in the form of either maps or aerial photographs or digital data is generally available for sale for all users, government or private at a nominal cost, with the exception of large scale data of certain security wise sensitive areas. The cost and the available formats can be obtained from the Survey Department web site www.survey-dept.slt.lk. When the digital data is sold the purchaser is expected to enter an agreement with the Survey Department saying that the data cannot be copied and supplied to any other party without prior approval of the Survey Department. We also have certain rules and regulations governing the reproduction of geo-spatial data obtained by the Survey Department. It says permission should be obtained by paying royalty calculated based on the area covered and the number of copies reproduced.

Issues
Many organizations in Sri Lanka have started converting the topographic and thematic maps produced by the Survey Department, into digital form. This has been done in rather ad-hoc manner without proper coordination and knowledge between different organizations, resulting repetition of work, also without a proper standard and accuracy required for the dataset. There is tremendous number of digital geo-data sets generated and maintained by different organizations, but they are not compatible to each other because they are from different hosts, different data sources and different data structures.

Geo-information is associated with high costs involved in data collection and compilation. The Sri Lankan situation in this regard has even gone to the extent of wasting public resources, and producing unreliable results for the decision makers who use the GIS technology for planning purposes. Hence there is an utter need for exchange and sharing of Geo information. Therefore there is an urgent need for a clear vision on the future handling of geographic information in Sri Lanka, taking into account of modern developments and trends in information technology and needs for the country.

Having taken the above facts in to account, a proposal has been forwarded to the government to establish a National centre for GIS to setup and maintain the foundation geo-spatial data set for the other organizations and users to add any thematic dataset of their interest.