A cadastral map refers to a map that shows the boundaries and ownership of land within specified area. Some cadastral maps show details including district names, unique identifying numbers for parcels, certificate of title numbers, positions of existing structures, section or lot numbers and their respective areas, adjoining and adjacent street names, selected boundary dimensions and references to prior maps.
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The cadastral map has four main purposes:
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Provides a cartographic record of official and sometimes private land surveys and subdivisions.
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Facilitates the administration and transfer of land ownership.
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Records land ownership.
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Assists in the valuation and taxation of land.
Digitization is the most important technique of data and storage in a GIS but is expensive and time consuming. Behind the success of this mapping technology is a major role played by the technology of capturing data in digital form. Data forms the backbone of the GIS industry. Spatial data is available mostly in analogue form i.e. in the form of maps, imageries, aerial photographs etc. Perhaps the biggest bottleneck in the GIS industry is the proper reproduction of the analogue data into digital form. The process of converting an analogue map into a digital format is known as “Digitisation”. The digital capture of data from the analogue sources viz. maps, imageries, aerial photographs etc. is carried out in two different methods, manual digitisation and heads up digitisation.
Remote sensing is the science of obtaining the physical properties of an area without being there. Remote sensing offers a cost-effective method to capture field data for analysis and planning purposes. Some projects require acquisition of information on objects and phenomena at a large scale. Physical survey in such a situation is not a viable option. Remote sensing is a technique that is time and cost effective and is therefore apt for such projects.