There are many possibilities for saving attribute data in DWG files. AutoCAD can convert DWG files to DXF files without loosing graphic information. DWG, Autodesk Drawing FilesĭWG is an intern format for AutoCAD. This format is mainly used by the USGS and other American agencies, which have used it for publication of many digital maps. DLG does not contain any visualisation information (display). It contains very precise coordinate information and sophisticated information about object classification, but no other attributes. DLG, Digital Line GraphsĭLG is used by the US Geological Survey (USGS) for handling vector information from printed paper maps. DGN files contain detailed visualisation information (display). This format is well documented and standardised, which makes it possible to use it an import/export format. DGN, MicroStation Design Files:ĭGN is an intern format for MicroStation, a CAD program (CAD means “Computer-Aided Design”). Simple ASCII format which can handle point and line data. It should be noted that this list is far from being complete! Vector Formats These functions are usually well documented and standardised.īelow is a list of some GIS file formats, in alphabethic order. Nevertheless, most GIS programs support other formats by having functions to import and export datasets. These file formats were created to optimise the efficiency of the program itself, and were not designed to be used in other external programs. Nearly all GIS programs have their own file format. If you want to use GIS data that was saved in a particular format not supported by your GIS program, you must either find a way to transform the data or simply use another GIS program.
It is important to consider the file format of GIS data because software programs rarely support all file types. There are numerous formats available for both raster and vector data. Raster and vector data are stored in different formats. Some organizations use File Geodatabase internally which is OK if everyone has access to ArcMap.File formats define in which way the geographical features are stored. These formats are not recommended for distributing data. Only used for visualizing data, not for distribution (does not include a SRS).The main format for data for GoogleEarth.Good option for complex datasets such as all the GIS layers for a town as long as everyone has ArcGIS.Commercial, has compatibility problems, and needs to be zipped if used for distribution.Raster and Vector data can be obtained in a variety of "complex" formats, such as: In both cases, the width and the height of the pixels has to be specified. This would put the lower-right corner, 30,000 meters to the west and south of the upper-left corner of the raster. For a LandSat scene the width and height might be 1000 pixels and the width of each pixel would be about 30 meters. The location of the other corners are computed using the width and height of the raster in pixels and the width and height of each pixel in "map units".
In the second case shown below, one corner has been specified. The location of the other corners can be computed by simply combining values form the other corners. In the first case, the location of the raster is specified (georeferenced) simply by providing the coordinates of two corners of the raster, typically the upper-left (north-west) and the lower-right (south-east). There are two methods for georeferencing a raster to the earth: Other formats can be used to publish maps in reports and web pages. See the "Quick Reference" on Jim's site under " resources" for additional information on raster file formats. We recommend using the IMG file format with ArcMap and TIFF for other GIS applications. Coordinates to "georeference" the raster at the corners.To use a raster, we need the following information: There are a huge number of raster files formats. This feature does not work well with tools and the data should be exported to a new shapefile to avoid problems. This will appear after the name of the layer and also appears when creating selections from other layers. Note: ArcMap has a new feature that imports tabular data as "events".
TXT: Typically tab-delimited but can be commas, pipes ("|"), or other charactersĪrcMap can access most of these files by using the "Add X,Y" data feature but it is best to then convert these files to shapefiles.Point data is simpler than polyline and polygon data and can be provided in a simple "table" format. You may find vector data in other formats but it is best to convert them to shapefiles for use in ArcMap.
The challenge is to know which file formats you can convert into a standard format and how to find the software to do the conversion. You may find data in a wide variety of formats. File Formats and Complex Formats (Raster and Vector)