June, 1997 (Vol. 26, No. 1)
Refereed Papers
Nairn, A. and Irwin, B. (1997) The Australian Spatial Data Infrastructure: Its current status and future directions, Cartography, Vol. 26, No. 1.
Featherstone, W.E. (1997) A comparison of existing co-ordinate transformation models and parameters in Australia, Cartography, Vol. 26, No. 1.
Lin, H. (1997) STIN operation: A study on searching for spatiotemporal measures, Cartography, Vol. 26, No. 1.
Olliver, J.G. (1997) A transformation procedure for digitising Defense Mapping Agency air navigation charts, Cartography, Vol. 26, No. 1.
Contemporary Cartography Papers
Gentilli, J. (1997) The use of thematic maps to aid research , Cartography, Vol. 26, No. 1.
The Australian Spatial Data Infrastructure: Its current status and future directions.
Alister Nairn
Acting Manager, Spatial Data Infrastructure Program
Australian Surveying and Land Information Group
Canberra
Bob Irwin
Spatial Data Infrastructure Program
Australian Surveying and Land Information Group
Canberra
Abstract
The concept of a national infrastructure is not new. The major road and telecommunications networks, and basic health and education facilities have been funded by
governments around the world to ensure that consistent infrastructures are developed in the national interest. In a similar manner, spatial data requires an
infrastructure to provide the availability and quality of spatial data in the application of high-benefit GIS applications. The government and the academic and private
sectors all have a role to play in the Australian Spatial Data Infrastructure (ASDI). The Australia New Zealand Land Information Council is promoting the ASDI
within Australia with support from other coordinating bodies, while the Australian Surveying and Land Information Group is taking a lead role at the Commonwealth
level. Input to the debate on the nature of the ASDI is encouraged from all sectors of the spatial data community, particularly during the developmental stage of the
infrastructure.
A comparison of existing co-ordinate transformation models and parameters in Australia
W. E. Featherstone
Senior Lecturer in Geodesy
School of Surveying and Land Information
Curtin University of Technology
GPO Box U1897
Perth WA 6845 Australia
Editor's note: This paper is a joint publication by the Institution of Surveyors, Australia and the Mapping Sciences Institute, Australia.
Abstract
Four standard procedures to transform curvilinear co-ordinates from the Australian Geodetic Datum 1984 to the World Geodetic System 1984 are compared.
These comprise the Bursa-Wolf model with the national set of seven parameters currently used by Federal and State surveying and mapping authorities, the standard
Molodensky model with the five parameters used by the United States Defense Mapping Agency, the simple three-parameter model with the origin shifts taken from
the Bursa-Wolf and standard Molodensky models, and the multiple regression equations as determined by the Defense Mapping Agency. The differences between
the resulting co-ordinates can reach 4.2 metres over continental Australia, which has implications for the final approach adopted to transform to the Geocentric
Datum of Australia. The arguments are presented in favour of more suitable transformation strategies using projective transformation models, which are able to
simultaneously correct any known errors existing in the Australian Geodetic Datum. These models also allow the direct transformation of both Australian Geodetic
Datum 1966 and Australian Geodetic Datum 1984 co-ordinates in a single procedure, which will be of benefit to those States which rely upon older geodetic
datums.
STIN operation: A study on searching for spatiotemporal measures
H. Lin
Department of Geography
The Chinese University of Hong Kong
Shatin, New Territory, Hong Kong
Tel: (852)-2609-6528
Fax: (852)-2603-5006
Email: huilin@cuhk.edu.hk
Abstract
Spatiotemporal synthesis needs an integration of the spatial and temporal elements of phenomena. Geographic information systems (GIS) have the capability of
enabling spatiotemporal synthesis. The spatiotemporal intersection (STIN) model discussed in this paper is a study of spatiotemporal synthesis for GISs. The aim of
this study is to provide a spatiotemporal measure for spatiotemporal correlation analysis. GISs are considered to be the visualization environment for a higher
dimensional (3D or 4D) analysis of spatiotemporal pattern.
A transformation procedure for digitising Defense Mapping Agency air navigation charts
J.G. Olliver
Department of Earth Sciences
Oxford University
Abstract
The mathematical transformation for converting coordinates digitised from the Defense Mapping Agency 1:1 million Operational Navigation Chart, the 1:2 million Jet
Navigation Chart and the 1:500,000 Tactical Pilotage Chart map sheets into latitudes and longitudes is described. A least squares adjustment is employed in order to
improve the accuracy, and to provide a check on the quality of the digitisation.
The use of thematic maps to aid research
Joseph Gentilli
Hon. Senior Research Fellow
Department of Geography
University of Western Australia
Nedlands 6907
Abstract
Thematic maps can be effective tools in the course of research, as well as very effective means of communicating stages in research progress, and findings, be they
tentative or final. When maps are used as research tools they may help, for instance, by showing actual gaps in the data available, or the adequacy or otherwise of
the class intervals chosen. They may also reveal similarities or associations, some of them perhaps previously unsuspected. Choropleths or isopleths may be used, the
latter affording greater scope for interpretation. Thematic block diagrams are seldom used; although they may be a great help in communicating complex links and
flows. Colour is usually far too expensive to print; however when the economy allows it, its use should be planned very thoroughly.
This paper aims to demonstrate how thematic cartography may be used to enhance the presentation of results of research endeavours, and convey greater meaning
to the reader.
|
