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“Low Cost Amateur Aerial Pictures with Balloon and Digital Camera” introduces and assesses the highly efficient amateur aerial balloon photo technique which makes aerial photos affordable at a price of 0.10 – 0.35 US cents per hectare. The idea is to provide an inexpensive but quality efficient solution for recent aerial color photos on a high pixel resolution as orthophotos, which are either not available or not accessible in many developing countries.
Other high resolution images from advanced satellite scanners like Quickbird, Ikonos or others are unaffordable to many low budget projects as well as to sub-ordinate planning institutions. As a consequence, topographical and high-resolution spatial data is more or less unavailable in those planning offices. Because of this, planning if often based on out of date topographic and thematic maps, while the situation in the real world has considerably changed. Especially on lower planning levels (e.g. provincial, distict, municipality or community planning) this method is an approach to generate a snapshot of the real situation on a low budget basis.
This modern technique is based on a simple plastic balloon (r=3m), inflated with hydrogen gas, chemically produced on the site and adapted to the conditions in developing countries especially for flat areas with rapid land use changes. Additionally, a digital camera is required, and some modifications have to be possibly made in order to remote control the camera, which, attached can reach a height of up to 1000 m above the ground.
The rectified, merged and geo-referenced aerial balloon-photos with a surface resolution per pixel of 20m to 0.4m, depending on altitude of the platform and camera capacity, can be enlarged up to a scale of 1:800 without any loss in optical and spatial quality. Methodologically the approach uses typical image processing, enhancement and geo-referencing techniques like haze elimination, merging and mosaic procedures, mostly provided by ERDAS IMAGINE software. The aerial photo collection follows standard aerial photo measures like flight line preparation, synchronization of camera and GPS clocks as well as ground truth samples.
Further outcomes of this technique are up to date detailed land use maps as well as other planning sources for real estate validation and environmental protection strategies i.e. buffer zoning concepts. Besides, they are expected to be useful for other “small area” projects like village based land use planning, technical implementations or (eco-) tourism projects at specific locations and retakes of the same photos within a high-level time resolution of one or two years. |