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GEODATA TOPO-250K (Series 1) Topographic DataNote: This metadata describes the dataset in accordance with the ANZLIC (Australia New Zealand Land Information Council) Core Metadata Guidelines Version 2. Dataset citationANZLIC unique identifier: ANZCW0703005661 Title: GEODATA TOPO-250K (Series 1) Topographic Data CustodianCustodian: Geoscience Australia Jurisdiction: Australia DescriptionAbstract: Contains a medium scale vector representation of the topographic mapping features of Australia. The data include the following themes: Hydrography - drainage networks including watercourses, lakes, wetlands and offshore features; Infrastructure - systems for the transportation of goods and services, ie. roads, railways and associated structures, along with localities, built-up areas and aeronautical features so that these services may be located; and Relief - a series of spot elevations, chosen so as to give a representative picture of the terrain. The topographic map and data index gives coverage information. ANZLIC search words:
Spatial domain:
Geographic extent name: AUSTRALIA EXCLUDING EXTERNAL TERRITORIES - AUS - Australia - Australia Geographic extent polygon: 112 -9, 154 -9, 154 -44, 112 -44, 112 -9, Note: The format for each Geographic extent name is: Name - Identifier - Category - Jurisdiction (as appropriate) See GEN Register
Data currencyBeginning date: Not Known Ending date: 1994-01-01 Dataset statusProgress: Complete Maintenance and update frequency: Irregular Access
Access constraints: The data are subject to Commonwealth of Australia Copyright. A licence agreement is required and a licence fee is also applicable. Data qualityLineage: The TOPO-250K product is primarily sourced from the 1:250 000 scale National Topographic Map Series (NTMS) and the Royal Australian Survey Corps' Joint Operation Graphics (JOG) map reproduction material (repromat). Additionally, digital information for Tasmania was provided by the Mapping Division of the Tasmanian Department of Environment and Planning and base mapping material for two map areas was provided by the Department of Land Administration, Western Australia. Where NTMS and JOG maps were published for the same area, the repromat used for the printing of the maps with the latest reliability date was used as the source. Where both map series were published with identical reliability dates, the NTMS material was used. A full description of the production method is provided in the TOPO-250K Data User Guide supplied with the data. Positional accuracy: TOPO-250K data complies with the following statement of horizontal accuracy: "The summation of errors from all sources results in data with a standard deviation of 100 metres for well defined features". Alternative and equal ways of expressing this error are: Not more than 10% of well-defined points are in error by more than 160 metres; and In the worst case, a well defined point is out of position by 300 metres. As the TOPO-250K data were digitised from existing map production material, some features may be subject to cartographic displacement. A full description of the features that may have been displaced and the range of displacement that may have occurred due to generalisation are provided in the TOPO-250K Data User Guide supplied with the data. The accuracy of the spot elevations in the relief theme varies with the type of source from which they were taken. Each of the following point determinations show the standard deviation of their Elevation and Horizontal accuracy respectively: - Spot height: 5 metres, 50 metres - Point from 20m contour: 10 metres, 50 metres - Point from 40m contour: 20 metres, 50 metres - Waterline: 25 metres, 100 metres Attribute accuracy: For the TOPO-250K product, attribute accuracy is a measure of the degree to which the attribute values of features agree with the information on the source material. The allowable error in attribute accuracy ranges from 0.5% to 5%, at a 99% confidence level. Where less than 1% of attribute errors are permissible the entire population is tested. Where a less stringent limit is set for allowable errors a random subset of the relevant features in the tile is generally tested. The sample size is determined from statistical tables using the known population size of the relevant feature. A full description of the checks on the data, the test sample size and the allowable error are provided in the TOPO-250K Data User Guide supplied with the data. Logical Consistency: For the TOPO-250K product, logical consistency is a measure of the degree to which data complies with the technical specifications. The data were tested using a mixture of UNIX scripts and ARC/INFO commands which were independent of the production system. Graphical tests were used to check such things as intersections, polygon closure, minimum size of polygons and topological relationships. A full description of the checks on the data, the test procedure, test sample size and the allowable error are provided in the TOPO-250K Data User Guide supplied with the data. Completeness: All instances of a feature and its attribute values that appear on the source material have been captured unless otherwise stated in the selection criteria for that feature provided in the TOPO-250K Data User Guide supplied with the data. The completeness was tested by overlaying symbolised plots of the data on the source material and carrying out a visual comparison. Contact information
Metadata informationMetadata date: 2009-03-31 Additional metadataMetadata reference XHTML: http://www.ga.gov.au/meta/ANZCW0703005661.html Metadata reference XML: http://www.ga.gov.au/meta/ANZCW0703005661.xml Size of dataset: 540 tiles, 3 themes per tile. An average of 3 to 9 mb file (all themes) depending on format Scale/resolution: 1:250 000 |
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