Map making has, since the dawn of the modern era, been as much an art as a science. To be sure, maps are a record of the ground as it is discovered to be, subject to all the usual vagaries of accuracy and completeness. But they are also objects of beauty, perhaps even cultural treasures, because in many ways they provide a window into the way a society thinks.
This will remain true, but just as society is been churned by the winds of change, so too, cartography is changing. We are in the middle of a revolution in the way maps are made. People have been talking about it for years, but it seems that now decisions have been made that will take cartography well into this new, data-obsessed century.
Increasingly, maps are an anachronism. Apart from any other consideration, they are inevitably out of date before they are published.
It is instructive that some of the first (1995) revisions of the latest wide-area maps of Australia, Geoscience Australia's 1:250,000 scale Natmap series 2 paper charts and Geodata Series 2 digital data, are based on satellite imagery obtained in 1994. On average, the data in these series is between one and two years old even before the charts hit the shops.
As these things are counted in traditional map-making circles, the Natmaps form an up-to-date map series.
The problem is, of course, that they do not fulfil the requirements of the huge body of users that are potentially available to the next generation of cartographers.
These users -- the trendy young things with their mobile phones, the Internet surfers -- have a completely different set of requirements from those of traditional users. They need maps that are complete and dynamic -- essentially, immediacy is a must.
All this is well understood in the map-making community. There is also widespread agreement on how to solve the problem, but perhaps less unanimity on where the money to do it should come from.
The solution is to use a database as the fundamental repository of spatial information, and to use paper maps merely as a means -- only one means -- of displaying that information.
This understanding has been around for quite some time, but it has only now begun to manifest itself in a way that is making a difference to the way organisations work.
Recently, the National Mapping Division of Geoscience Australia has begun to fundamentally rethink the way it carries out its map updating. It turns out that the process has great implications for the way spatial data is displayed, and the way maps are produced.
The NMD has a number of paper products that begin at 1:100,000 scale. It also produces a 1:250,000 series, one at 1:1 million, one at 1:2.5 million and some individual Australian maps at smaller scales. The 1:100,000, 1:250,000 and selected smaller scales are also available as digital maps. Larger-scale maps exist, but they are the responsibility of state and local government jurisdictions, and never have nationwide coverage. Maps are also produced over selected areas for Defence use, at 1:50,000 and 1:25,000 scale. The production of these maps is now managed by NMD.
Of these, the 1:100,000 map sheets are in much the worst shape. The majority date from the 1970s and 1980s, and are not useful for many purposes as a result. In many cases they remain the best available published maps and are still called on in large numbers, particularly in emergency situations such as the recent bushfires.
In 2000 the NMD's predecessor, AUSLIG, put together a well thought-out proposal to upgrade the whole series, but it was knocked back in the federal budget process that year. Nevertheless, Ian O'Donnell, the group leader responsible for mapping and maritime boundaries at NMD, points out that 60 of these maps have been updated, because of an additional $2 million of Commonwealth funding over the last five years.
Alister Nairn, the group leader responsible for product management at NMD, says the 49 sheets in the 1:1 million series have not been upgraded since the 1970s and early 1980s. However, a related digital product based on the Global Map project, which is available on the web, and contains updated information based on Series 2 Natmaps and Geodata, has largely superseded it. Consideration is being given to updating the 1:1 million map series based on the Global Map and 1:250,000 Series 2 Geodata.
Clearly, much of this is unsatisfactory. Also clearly, it is the result of budget decisions made on a political basis, which say that the money would be better spent in other areas.
Whether that is a good decision or not is beyond the scope of this article, just as it is beyond the power of bureaucrats in the mapping infrastructure to change it. What is not at issue is that funding puts tight constraints on what is possible. To their credit, rather than bewail their fate, the bureaucrats in NMD have responded in two ways: by considering how to do more with less, and by considering creative ways to obtain more funds.
There are a number of government departments who would dearly like an accurate 1:100,000 coverage of the country -- people concerned with emergency management, environmental management and land use not least among them. The question in Canberra, then, is whether they might be prepared to foot at least some of the bill to make it happen.
As to doing more with less: there are two principal ideas. One is to use new technologies as part of the map updating process. In particular, new pricing policies for some of the space-based imagery that has recently become available makes all the difference to the cost of an updating program. The current revision of the Natmaps relies on traditional imagery from Landsat and SPOT, but there is a great deal of interest in the offerings of the latest SPOT-5 instrument, as well as from satellites operated by DigitalGlobe and Space Imagery.
For map updating, these satellites offer imagery that is not too dissimilar to aerial photography, but comes at less than the cost of a full-scale aerial photography mission. However, obtaining this imagery is still an expensive undertaking.
Another potential player in this field is the upcoming Japanese ALOS satellite, which is especially designed for mapping. Its PRISM instrument (Panchromatic Remote sensing Instru- ment for Stereo Mapping) will yield 2.5 metre pixels, which is perfectly adequate for 1:100,000 mapping. For public good mapping programs, such as those run by NMD, the Japanese have indicated the data will be provided free. Peter Holland, the general manager of NMD, said licensing conditions attached to the downstream use of ALOS data are still to be negotiated.
The other idea is to completely rethink the relationship between maps and the data that underlies them. This has led to proposals to develop a seamless object-oriented map database (OOD) of Australia that will drive all of the NMD's mapping output.
The strategy is that the database that lies behind the current revision of Geodata Topo-250K Series 2 (which is at 1:250,000) will be used to build a seamless data- base of the continent.
This has significant implications for the way the data is upgraded. It will no longer be necessary to upgrade entire tiles. Upgrading can be done on a theme-by-theme basis, over any convenient geographic area, by anyone with an interest in current data.
For instance, O'Donnell says his group is currently investigating the supply of information about vertical obstructions (towers etc) within Australia so that a quality database can be built. These features change on a daily basis, so it could form the first of many dynamic layers in the OOD.
Holland says this example is also instructive because of the use of a commercially driven organisation -- Telstra -- to supply the data. Holland says the OOD implies a whole new arrangement between the private and the public sector. All kinds of arrangements for data supply and data use will become technically and economically feasible.
Nor is there any reason to restrict the OOD to 1:250,000 scale mapping. It is quite feasible to store data at larger scales -- 1:100,000, or even larger -- as and when it becomes available. It is quite conceivable, for instance, that future upgrades of particular features, such as roads or streams, might occur at large scales.
Potentially, of course, there is no reason why such a database needs to be restricted to the historical mapping concerns of the national mapping agency. In Australia, the largest-scale maps are the responsibility of state or local government organisations. Driven by the Intergovernmental Committee on Surveying and Mapping, all state and Commonwealth mapping agencies are now focused on building maps from data in databases structured according to a common data model.
In theory, there is no reason why data created at the largest scales could not be transferred at will between databases. This data could then be used to create whatever products were desired, with profound consequences for the accuracy and currency of the resulting products. Indeed, such a concept has been under discussion for quite a while by ICSM, although Nairn says one should not minimise the technical or institutional difficulties.
Nevertheless, it seems that despite, or perhaps because of government's parsimony, cartography is evolving towards a truly dynamic representation of the Earth. The new cartography will still produce a representation of this planet, as it has always done, but like our current age, it will be up to date. Whether there is a space in there for the artist is a moot point.
