Extract from an email recerived from Geoscience Australia
Thank you for your feedback on possible shortcomings in the accuracy of our 1:250 000 maps.
The production of these maps has been undertaken using the following criteria:
Data was converted from our printed maps to digital mapping format.
Satellite imagery (best available at the time) was obtained to update the information shown on the map.
All available mapping information published over the area both Government and commercial mapping was sourced.
In a majority of the central part of Australia we were able to draw on the resources of GPS surveyed public roads and tracks.
Using this information we updated the maps using the premise that if we can not confirm that a feature does not exist it is retained as captured in our major mapping program of Australia. The assembly of our original mapping information entailed an extensive program of field verification to confirm the existence of homesteads, bores, windmills and fences and to remove these features without supporting reference may be more dangerous to map users.
We are aware of shortcomings in this method of updating however it was the method within our budget that would provide Australia with 513 maps at a consistent scale of 1:250 000 of Australia.
The digital data used to produce these maps is now assembled into an Australia wide database and over the past three years we have identified areas of change or subject to development applications. Maps are currently being revised in these areas to available information.
Our limited resources do not permit us to undertake detailed field inspection of all map sheets and we are therefore very dependent on information supplied by concerned map users as you.
Addressing the issues raised in your email we can confirm that we are undertaking a major review of the
Flinders Ranges area in collaboration with SA Government agencies. Information obtained will be used to update our mapping database and activate the production of new maps of the area.
The depiction of
sand dunes at 1:250 000 scale is a selection of those depicted from mapping sources. Our intention is to supply sufficient information at scale to depict to the user the extent of
sand dunes. Please supply more information of the
sand dune height issue to enable investigation of our sources.
We have investigated the road detail in the
Broken Hill area to newer source information and we can confirm we will undertake a review of this information. Once again, if you are able to supply more information obtained from your travels to assist in this matter it would be greatly appreciated.
As you can gather we are very receptive to feedback from our map users. Receipt of any information is investigated and confirmed from additional mapping sources. The mapping database is subsequently updated and this new information will flow through to maps produced of the area.
The product ‘Digital Maps 2008’ of the 1:250 000 maps is now available. A major enhancement to the graphical user interface permits the display of the map and satellite image ‘split screen’ or to use the map as a transparency over the image. The maps have been produced from our mapping database with edge match consistencies removed between the 513 maps. Some updated information will appear on these maps that has not yet flowed through to the printed product and this relates primarily to new roads etc in the populated areas of Australia.
Once again thanks for your feedback and we await the supply of any additional information that will assist in updating our maps.
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I shall be replying in due course giving details of my findings.
Cheers