Sample Thesis Paper
Virtual globes combine topographic representations of the Earth’s surface with satellite images and are currently used by hundreds of millions of users worldwide to visualise the planet’s surface. These software systems have been characterised as “GIS for the masses” bringing the geomorphology of the Earth into the user’s home, as a cost-free imagery source. Google Earth (GE) is by far the most popular geo-browser. The GE model consists of hundreds of thousands of individual satellite and aerial images stitched together from a variety of commercial sources such as Landsat and QuickBird satellites, and providers of aerial photographs from 2000-2008. The end result is a high-resolution view of the Earth with resolutions varying from < 2.5m for urban areas to only 15-metre Landsat resolution particularly in rural areas and developing countries. Imagery of this resolutions allows relatively accurate identification of man-made structures such as building, houses, roads and bridges. Land cover types and distrurbance events can also adequately visualised (Potere 2008). GE’s images are fully georeferenced, with options to display relevant coordinates, spot elevations and place names.GE users can rely upon a well-established user community for updates of satellite imagery, although there have been sporadic reports of updates from Google itself (Potere 2008).
The potential of GE and possibly other virtual globes to be therefore exploited as tools for environmental monitoring has already been recognised by scientists in other disciplines as a visualisation platform for scientific reasearch (Tooth 2006). An obvious potential scientific use of GE is as a supplement and aid to geomorphological research, assisting in fieldwork planning, data collection and surveys. GE’s 3D terrain visualisation can be utilised in the preparation stages of field studies, where aerial photographs are currently used to assess the field study area. GE can also be used to assist in the study of areas which suffer from maps inconsistencies and limited aerial photography coverage, as a fast, cost-effective method. Potere (2008) attempted to compare the horizontal position accuracy of GE with LandsatGeoCover scenes sample of 436 control points located in 109 cities worldwide.