DLG File – What is .dlg file and how to open it?
DLG File Extension
Digital Line Graph – file format by N/A
DLG (Digital Line Graph) is a vector data format developed by the USGS to store spatial data. DLG files contain line features, such as roads, rivers, and boundaries. They are used for a variety of applications, including mapping, land use planning, and environmental modeling.
Definition and Usage
A DLG file, short for Digital Line Graph, is a vector data format designed to store geographic information. It was initially developed by the United States Geological Survey (USGS) in the 1970s to digitize topographic maps, and has since become a widely recognized standard for representing geospatial data. DLG files are used in various applications, including cartography, land use planning, natural resource management, and environmental modeling.
Structure and Features
DLG files consist of a series of records that describe the geometric features (points, lines, and polygons) and their attribute information. Each record contains specific codes and data values that define the shape, location, and attributes of the features. DLG files can contain multiple layers of geographic data, allowing users to represent complex geographic relationships and features. The file format supports various geographic projections, coordinate systems, and data formats, providing flexibility for different applications.
Opening DLG Files in ArcGIS
To open a DLG file in ArcGIS, follow these steps:
- Launch ArcGIS and create a new project.
- In the menu bar, click on “File” and select “Add Data”.
- Navigate to the location of the DLG file and select it.
- Click “Add”.
The DLG file will be added to the map as a feature layer. You can now view and edit the data as needed.
Other Methods to Open DLG Files
In addition to ArcGIS, there are other software programs that can be used to open DLG files. These include:
- Quantum GIS (QGIS): QGIS is a free and open-source GIS software that can be used to open and view DLG files.
- Global Mapper: Global Mapper is a commercial GIS software that can be used to open and edit DLG files.
- AutoCAD: AutoCAD is a commercial CAD software that can be used to open and view DLG files.
Once you have opened a DLG file using one of the aforementioned software programs, you can view and edit the data as needed. DLG files contain a wealth of geospatial data, including information on roads, railroads, rivers, and other features. This data can be used for a variety of purposes, such as planning, development, and environmental assessment.
DLG File Structure
DLG files contain geospatial data in the Digital Line Graph format. They are vector formats that represent linear features such as roads, streams, and boundaries. The data within a DLG file is organized into different layers, each containing a specific type of feature. DLG files typically consist of two main sections: the header and the data. The header contains general information about the file, including the number of layers, the extent of the data, and the projection used. The data section contains the actual line features, which are defined by their coordinates and attributes. DLG files use a hierarchical structure, with each layer divided into subclasses and further into individual features.
Applications of DLG Files
DLG files are widely used in geographic information systems (GIS) for a variety of applications, including mapping, land use planning, and environmental modeling. They provide a detailed representation of linear features, making them valuable for analyzing the connectivity and network patterns of natural and man-made systems. DLG files are also used as reference data for other geospatial products, such as topographic maps and aerial imagery. Additionally, they can be converted into other vector formats, such as shapefiles and GeoJSON, for compatibility with a wider range of software applications.