Raster Data Formats used in GIS and Remote Sensing
Representation of Raster Data
Raster data representation of Features
- Points features by single cells
- Line by sequence of neighboring cells
- Polygons by collections of contiguous cells
Organization of Raster Data
Advantages of Raster Data Model
- Raster data model is capable to represent different types of continuous surfaces. Such as Topography, land use/land cover, air quality, ground water pollution level etc. can be stored at raster layers.
- Raster data model support fast computer processing. Such as fast display of surface data, ability to handle very large databases, Tiling, Compression to reduces storage requirement.
- Many spatial and modeling applications work only on data in raster format. For example, hydrologic modeling such surface runoff modeling, elevation modeling and pollution modeling
- Remote Sensing Data are the major source for input data in analysis is based on raster data model.
Limitations of Raster model
- Rater data model is not suitable for applications that rely on individual spatial features represented by points, lines and polygons. For example network analysis.
- Precise locations may not be recorded in raster data as compare to vector data.
- Features are usually generalized in raster data and do not appear as cartographically pleasing as vector data.
- Resolutionof raster data determines applicability of raster data. With the increase in resolution it increase data volume and affect the computer processing speed.