In Queensland we have produced topographic maps at varying scales since 1962.
The ad hoc approach to project mapping in the 1960s and early 1970s evolved into a standard mapping program in 1977. Topographic maps produced from 1971 onwards use a standard map numbering convention to define map sheet extents. The adoption of this standard base grid system for map sheets for all map scales not only topographic maps made it easier to plan mapping projects and simpler for map users to identify exact position and map sheet coverage.
Map production methods
Two methods were employed simultaneously for a number of years to produce topographic maps.
Those compiled using pen and ink were drawn at a scale of 1:16 667. They were then reduced two thirds at final negative stage for an output print scale of 1:25 000.
The second method involved a previously prepared fair drawing generally produced using photogrammetric machines which was photographically transferred onto a stud-registered negative emulsion. The contours and other line work were compiled on separate overlays using sapphire tips specially machined to different widths. The sapphire tip lifted the emulsion, resulting in a new negative. This did away with the earlier positive generation method. These 1:25 000 maps required no photographic reduction at the final negative stage. In time, scribing totally replaced pen and ink work.
In terms of text to be displayed on the maps, adhesive backed type for all nomenclature and miscellaneous text was affixed to clear stud-registered (positive) overlays according to final print colour requirements. A negative was then generated from each positive overlay.
Halftone screen work was produced via the process of cutting a mask to the desired shapes on a rubylith overlay. This was then exposed together with a screen overlay photographically to produce 6 negatives, one for each process colour to be used when printing the topographic map.
NOTE: Historical topographic maps can be accessed via the Queensland Globe by launching a Historical maps topic. It allows you to search for and access our department's released historical map scans for available Queensland locations.
Going Digital
In the early 1990’s, the department embarked on a program to collect topographic information in a digital format. Digital capture techniques completely replaced all manual forms of mapping, map production procedures were revised accordingly. Photogrammetric stereo plots were converted from analogue to digital output and a program to convert the existing map sheet-based themes into digital data, commenced.
Photogrammetric plots, each containing twelve control points, were scanned and digitised. The resulting raster image was edited, filtered, cleaned, and converted to two-dimensional vector data using specialised software.
The data was compiled in files representing themes using the map sheet number as the file identifier in an AS2482 Interchange Format. These files were stored as a library of CD’s and then on a data server, though no provision for corporate access to the data files was available. The data could now be manipulated, and styles applied within the software and digital topographic map sheets were generated.
Eventually, the individual digitalised map sheets were merged into digital datasets and stored in the Spatial Information Resource (SIR) environment in an Esri geodatabase. Managing the data as state-wide datasets within the SIR environment overcame the limitations of map sheet-based datasets stored in a library of CD’s. Metadata in ISO standard 19115 accompanies all the datasets. SIR was readily available to all GIS/Spatial officers across the state making the authoritative data instantly available to them.
Present Day
To this day, the Department of Resources remains as a source for spatial mapping of Queensland. Topographic statewide spatial data. The continue review and update of data, methods and documentation remain a priority for the Department. This is the core to provide accurate, consistent, reliable, timely and accessible spatial data which supports The Department’s open data strategy along with the Queensland Foundational Spatial Data Framework.
For further information, Visit Museum of Lands, Mapping and Surveying.
Queensland’s topographic features are depicted by digital data showing information about the nature of the land—both natural features and purpose-built structures.
|  Figure 2 - Topographic Data content (extracted from QTopo)
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