What are the key components of GIS?
A working GIS integrates five key components: hardware, software, data, people, and methods.
Hardware is the computer on which a GIS operates.
Today, GIS software runs on a wide range of hardware types, from centralized computer servers to desktop computers used in stand-alone or networked configurations..
What is attribute join?
Join the attributes from a table. … You can perform a join by using the Add Join geoprocessing tool. When performing an attribute join, the joined fields are dynamically added to the existing table. Field properties, such as aliases, visibility, and number formatting, are maintained when a join is added or removed.
How do I create a shapefile in erdas?
2 AnswersOpen AOI (that you wish to convert to a shapefile) in 2D View (table of contents)Create new shapefile (File > New > Vector Layer) Choose Polygon shape > OK.Select/Highlight AOI file in table of contents.Use Select tool (AOI tab > drawing tab) to select features from AOI you wish to copy.More items…•
What is a Relate in GIS?
Relating tables simply defines a relationship between two tables. … A relate is similar to a simple relationship class except it can involve data from different workspaces (such as a dBASE table can be related to a coverage) and is stored in a layer file or ArcMap document.
What is subset image?
A subset is a section of a larger downloaded image. Since satellite data downloads usually cover more area than you are interested in and near 1 GB in size, you can select a portion of the larger image to work with. … Open an image.
What is dissolve in GIS?
From wiki.gis.com. Dissolve is an application of the conceptual operators that aggregates features often referred to as ‘Merge’ or ‘Amalgamation. ‘ It is a process in which a new map feature is created by merging adjacent polygons, lines, or regions that have a common value for a specified attribute.
What is the difference between GIS and Qgis?
QGIS is an open source software and it is easy to access as compare to commercial software ArcGIS. … QGIS has less processing time and better rendering capabilities. • ArcGIS is preferred on QGIS because ArcGIS has better spatial topological analytical capabilities than QGIS.