Mapping, air photography, satellite imagery and Geographic Information Systems (GIS) Maps are a key to power. The leading cartographers of the eighteenth century were the French, who mapped their territories in the wake of Louis XIV’s great victories. Comprehensive mapping in Britain began after the Jacobite Rebellion of 1745 when the Scottish Highlands were first mapped. This led to the establishment of the British Ordnance Survey, which extended mapping activities first to Ireland and then to the British Empire. George Everest, director of the Great Trigonometrical Survey of India, completed the first triangulation of that country in the 1850s. This was a massive task that took half a century and involved building towers and clearing sightlines through forests. It has been argued that the American Civil War lasted as long as it did in part because comprehensive mapping of the country’s vast territories had not previously been undertaken. It has been suggested that if the terrain had been better understood, the Confederacy might have been defeated more quickly. The need for such maps led to the establishment of the US Geological Survey in 1879. All landscape architects should have a good knowledge of both mapping and its modern supplements, air photography
and satellite imagery. Begin by exploring the NASA website, which offers many views of the world, and also by reviewing the traditional mapping available in the country where you are working. The latter offers the additional advantage of allowing you to explore the recent historical layers of a site. For example, most developed areas of Britain were already mapped at larger scales of 1:1250 by the 1870s. Therefore you can plot the development of docks, roads, mines and quarries and their subsequent use for housing, or shopping centres or nature reserves over the past two centuries. Datasets are based on topographical mapping. For instance, in the UK the Ordnance Survey offers datasets such as OS Land-Form PROFILE Plus which is based on Ordnance Survey 1:10,000 scale mapping. Note: 1:10,000 map contours are at 5m intervals and are accurate to ± 1.0m in the countryside and ± 0.5m in some towns. However, it is also possible to use global navigation satellite systems or GNSS (sat nav) in mapping and surveying. GPS (Global Positioning Systems) is the best known and is based on US Department of Defense satellite data, but be aware that such data may only be accurate to a few metres, typically ±10m. Nevertheless, use
of such satellite-based data is critical in areas with poor topographical mapping coverage such as much of Africa and parts of the Middle East. There is only one other satellite-based global positioning system currently operational, the Russian GLONASS, with others in development in Europe, China, India and Japan. GLONASS is more accurate than GPS at high latitudes (i.e. the polar regions) and low latitudes (i.e. the equator). The European Union Galileo system may eventually offer the possibility of higher definition and accuracy (to within a metre) when it becomes available. This civilian-based system is designed to be operable with both GPS and GLONASS. The European Space Agency launched the first of the initial four Galileo satellites in October 2011. By 2019 there will be 30 satellites in total; the system is planned to be free for public use. The Chinese regional navigation system, BeiDou, is scheduled to be extended to cover the Pacific and Asian regions as BeiDou-2 (retitled as Compass) in 2012 and will have a free ± 1.0m service and a licensed, more accurate service, planned to go global by 2020. In 2012 BeiDou-2 is operating a free service with a ± 25m accuracy, this will become more accurate as more satellites are launched.
The European Union Galileo global navigation satellite system will offer superior resolution to the US GPS by 2020 while the Chinese BeiDou system is operational now. 4 Representing the Landscape Design Mapping, air photography, satellite imagery and Geographic Information Systems (GIS)
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