MAPOLOGY : GIS,Remote Sensing and Image Processing Tutorials

Some free but useful software for working in GIS projects are : MapWindow GIS,Quantum GIS etc. The steps for creating a Geo-referenced and informative spatial database( or database linked to spatial points) is the following : a)Selection of Coordinate System b)Creating shape-files(line for digitizing road,rivers etc;polygon for digitizing water bodies,plantations etc. and points for indicating cities,places etc.)  c)Creating the attribute tables linked to the shape-files where columns represents different attributes and rows represents the sub-shapes representing different features of same shape(artificial ponds can be digitized with polygon shape-files and each pond can be digitized within single shape-file where each sub-shape will describe that kind of pond only)  d)After relevant informations are entered into the attribute tables data-sets can be represented with the help of different colours or degree of colours or different styles. Each of the a...

Cover Feature: Shapefile is constructed to link a point in a digital map to a database storing related retrievable informations about the point. A vector data (points, lines, or polygons) storage format for storing the location, shape, and attributes of geographic features(ESRI Def). Shapefiles can be of three types : 1. Point Shape : A shapefile consisting of points which is used to represent datasets about a location(city,town etc.) 2. Polyline Shape : A shapefile of more than one point shape is known as Polyline shapefile and is used to represent information regarding line features like river,road,pipeline etc. 3. Polygon Shape : The polygon shapes are developed with the help of more than two points representing the vertices of a polygon.This type of shapes are used to exemplify a region like watershed,pond etc. Any shapefile can be zoomed in or out without any deformation in the spatial representation and thus such files are grouped under Vector images. Summary ...

Category Other Output Type Information/Fact TAG GIS Type of Message * Message Cover Feature GIS is defined as Geographic Information System .It is a tool to represent and/or retrieve data spatially.The spatially linked data are generally stored in a Geo-referenced database. Remote Sensing is a procedure to capture image of a remote object by various type of optical/thermal/sound wave active/passive sensors.Active sensors send an artificial signal (microwave or sound pulse) and capture the image by sensing the reflectance of the same where as passive sensors only detects or absorb light or any other naturally available energy signal reflected from the target object. Whereas Image Processing can be defined as the retrieval of information from an image by converting the same into DN values shown within the pixels(units which constitutes a raster image) of the image. ...