|
|
Acquiring GIS Data: Utah |
|||
|
Data Storage and Format: When working with GIS data, it is necessary to understand how various forms of GIS data are stored in their native format. This understanding is critical in order to be successful in moving GIS datasets around. For example, an ESRI shape file is not just one file but a grouping of multiple files that work together to create a more efficient method of storing spatial and tabular data, yet keeping the associations. Open ArcCatalog and Windows Explorer then navigate to the C:\esri\esridata\world directory. In ArcCatalog open the world directory by choosing the plus sign. In windows explorer show the directories as a list. (If you don't have the above data directory find any directory that contains an ESRI shapefile and make the same comparison) When you see an ESRI shape file, in this case country, in ArcCatalog Results: ( ArcCatalog_Shapefile ) we see only one file but if we look at it from Windows Explorer Results:( Win_Explore_shapefile ) we see that there are multiple files that make up an ESRI ‘shapefile.’ When moving an ESRI shapefile, with windows explorer, all these files must be maintained as a group, in order to recreate the original ‘shape file’ with all the appropriate associations. ArcCatalog recognizes the innate relationships and moves all the files by default when renaming or copying. An ESRI coverage is slightly different in how it is stored. An ESRI coverage is a combination of system directories and sub-files that have relationships (see the example below in the ‘ESRI Coverage’ section to understand the coverage file structure). |
||||
|
||||
Previous
