| Geographic Information Systems (GIS) have been a growing area of research with the increase of geographical data in real-world applications. Nowadays, web-based GIS, GIS combined with WWW techniques, have been developed in order to provide geospatial data to the general public. SouthDakotaView (SDView) is an example of a web-based GIS that provides satellite remote sensing data quickly and easily to users. The SDVis, which is a data service of the SDView website, is the South Dakota Version of the USGS Global Visualization (GloVis) for visualizing and downloading Landsat and other satellite data through the Internet. It is currently possible to download full-scene Landsat data from the SDVis. However, it is desirable to have the capability for "clipping" a portion of a single full scene or a portion of two or more adjoining scenes. This capability allows the user to download only the area of interest (AOI), saving download time as well as storage space. This area will be extracted from the full-scene datasets, and a metadata file will be created to accompany the extracted data file. The clipped file will then be put into a temporary directory, which will be delivered to the users. This thesis demonstrates such a clipping mechanism by developing a prototype system that provides a web-based interface for retrieval of an AOI of GeoTIFF format data. A Java servlet program and commercial off-the-shelf (COTS) software (ArcSDE, Microsoft SQL Server, and ArcIMS) are used in this approach. |
