LAYER NAME: Lakes - GA
TITLE:
GEODATA TOPO-250K Series 2 Topographic Data
CUSTODIAN:
Australian Surveying and Land Information Group (AUSLIG)
JURISDICTION:
Australia excluding external territories
ABSTRACT:
Contains a medium scale vector representation of the topography of Australia.
The data include the following themes:
Hydrography - drainage networks including watercourses, lakes, wetlands, bores
and offshore features;
Infrastructure - constructed features to support road, rail and air transportation
as well as built-up areas, localities and homesteads. Utilities, pipelines,
fences and powerlines are also included;
Relief - features depicting the terrain of the earth including 50 metre contours,
spot heights, sand dunes, craters and cliffs;
Vegetation - depicting forested areas, orchards, mangroves, pine plantations
and rainforests; and
Reserved Areas - areas reserved for special purposes including nature conservation
reserves, aboriginal reserves, prohibited areas and water supply reserves.
SEARCH WORDS:
BOUNDARIES LAND Geography VEGETATION
ENERGY LAND Topography WATER
FORESTS MARINE Coasts WATER Hydrology
FORESTS Natural MARINE Reefs WATER Lakes
FORESTS Plantation TRANSPORTATION WATER Rivers
HERITAGE Natural TRANSPORTATION Air WATER Wetlands
HUMAN ENVINONMENT TRANSPORTATION Land
LAND UTILITIES
GEOGRAPHIC EXTENT NAME(S):
Australia excluding external territories
BEGINNING DATE:
Not Known
ENDING DATE:
Current
PROGRESS:
In progress. For completed and forthcoming tiles see the AUSLIG Forward Program
MAINTENANCE AND UPDATE FREQUENCY:
Irregular
STORED DATA FORMAT:
DIGITAL, Vector Coverage
DIGITAL, ARC/INFO
DIGITAL, DXF
DIGITAL, MapInfo
NONDIGITAL, Printed Maps (See National Topographic Map Series 1:250,000 scale)
AVAILABLE FORMAT TYPE(S):
DIGITAL - Vector Coverage
DIGITAL - ARC/INFO
DIGITAL - DXF
DIGITAL - MapInfo
NONDIGITAL Printed Maps, (See National Topographic Map Series 1:250,000 scale)
ACCESS CONSTRAINTS:
The data are subject to Commonwealth of Australia Copyright. A licence agreement
is required and a licence fee is also applicable.
LINEAGE:
TOPO-250K Series 2 is primarily sourced from TOPO-250K Series 1 and 1:250 000
scale map reproduction material (from the National Topographic Map Series and
Defence Joint Operation Graphics). A key revision source for the data is satellite
imagery taken from the SPOT Panchromatic and LANDSAT Thematic Mapper Sensors.
Revision material has also been gathered from a variety of authoritative sources.
More information about the sources for this data can be found in AUSLIG's Topographic
Data and Map Specifications.
POSITIONAL ACCURACY:
AUSLIG has carried out both error budget analysis and field tests to verify
the positional accuracy of the data.
TOPO-250K Series 2 data complies with the following statement of horizontal
accuracy:
"The summation of errors from all sources results in data with a standard
deviation of 85 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 140 metres;
and
In the worst case, a well defined point is out of position by 300 metres. As
the TOPO-250K Series 2 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 Series
2 Data Quality Statement supplied with the data. An estimate of the standard
deviation of planimetric error of each feature instance is given in the Data
Quality Table.
Vertical Accuracy:
The accuracy of the spot elevations in the relief layer varies with the type
of source material from which they were captured and the point determination
for each particular point. Most spot heights have an accuracy of + or - 5 metres,
however bench marks and horizontal control points have an accuracy of + or -
1 metre. The accuracy of contours is defined as 1/2 of the contour interval,
for example + or - 25 metres for a 50 metre contour interval.
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. Further information on the validation and testing
methodology used by AUSLIG can be found in section 3 of the TOPO-250K GEODATA
Specifications.
LOGICAL CONSISTENCY:
Logical consistency is a measure of the degree to which data complies with the
technical specification. Validating logical consistency may involve tests to
check that table and file names are set out as in the Data Dictionary. Also
included are graphical tests which check such things as intersections, polygon
closure, minimum sizes of polygons and topological relationships. The allowable
error in logical consistency ranges from 0% to 5%. Further information on the
validation and testing methodology used by AUSLIG can be found in section 3
of the TOPO-250K GEODATA Specifications.
COMPLETENESS:
Completeness is a measure of the degree to which all features listed in the
technical specification have been captured, in accordance with the selection
criteria, definitions and other rules specified.
All instances of a feature and its attribute values that appear on the source
material are captured unless otherwise indicated in the selection criteria for
that feature.
CONTACT ORGANISATION:
Australian Surveying and Land Information Group (AUSLIG)
CONTACT POSITION:
Enquiries, Data Sales, National Data Centre
CONTACT PERSON:
Data Sales Staff
MAIL ADDRESS:
PO Box 2
SUBURB OR PLACE OR LOCALITY:
BELCONNEN
STATE OR LOCALITY:
ACT
COUNTRY:
Australia
POSTCODE:
2616
TELEPHONE:
Australia Fixed Network number
+61 2 6201 4340
Australia Freecall
1800 800 173
FACSIMILE:
Australia Fixed Network number
+61 2 6201 4381
ELECTRONIC MAIL ADDRESS:
datasales@auslig.gov.au
METADATA DATE:
15DEC1998
ADDITIONAL METADATA:
The Australian Spatial Data Directory(ASDD)
Also, further information about Spatial Metadata is at ANZLIC http://www.anzlic.org.au/metaelem.htm
ATTRIBUTES
aircraft facility type name reserve authority code
average height of sandridge national route number road - classification
benchmark code park code road - formation
building code perenniality source of spot elevation
contour code point determination for spot elevation state
data quality pointer product code state route number
description of landmark feature railway guage stream heirarchy
elevation railway status tracks
facility type reef code unique feature identifier
locality type relationship to ground/sea level waterpoint code
SCALE/RESOLUTION
1:250 000
RESTRICTIONS ON USE
None
SIZE OF DATASETS
540 tiles, 5 themes per tile
average of 10 mb per file (all themes) depending on format
PRICE and ACCESS
$100 per tile (all themes included)
Generous bulk discounts apply
AVAILABILITY of SAMPLE DATA
Available on the web at
http://www.auslig.gov.au/products/digidat/smpldta.htm
PROJECTION and DATUM
Datum: GDA94
Projections: Geographical - latitude and longitude
4.10.00 - added Perth, Ajama and Geraldton 250K lakes and wetland data.